Machine learning speeds up heterogeneous catalysis simulations dramatically

Good news! This is only the beginning!

"In heterogeneous catalysis, calculations require complicated computational processes due to the variability of reaction pathways and possibilities. Now, thanks to a clever combination of programming and machine learning, researchers have achieved a dramatic increase in the speed of simulations, enhancing the energy efficiency of an otherwise resource-hungry process. The results, reported for reactions to convert carbon dioxide into fuels, could rapidly translate into other industrially relevant reactions, such as depolymerisation and biomass valorisation. ...

Whereas traditional density functional theory (DFT) programmes predict up to 500 steps in 100 processing hours, this new solution speeds the search by orders of magnitude – simulating 370,000 possible pathways in a similar time. ..."

From the abstract:

"The rationalization of catalytic processes relies on the fundamental understanding of competing reaction mechanisms driving reactants to products. The list of elementary steps composing the reaction networks is proposed based on chemical intuition and evaluated via density functional theory. This approach is limited by the size of the network and disregards alternative paths.

Here we present the Catalytic Automated Reaction Evaluator (CARE), a flexible end-to-end framework for heterogeneous catalysis composed of

(1) a rule-based reaction network generator,

(2) a thermodynamic and kinetic parameter evaluator powered by state-of-the-art machine learning models and

(3) a fast microkinetic solver.

CARE reproduces the experimental activity trends in methanol decomposition, identifies the selectivity to C3 products in CO2 electroreduction and generates the Fischer–Tropsch synthesis mechanism including 370,000 reactions reaching C6 products. This comprehensive framework enables the exploration of thermal and electrocatalytic reactions previously not amenable to atomistic simulations."

Machine learning speeds up heterogeneous catalysis simulations dramatically | Chemistry World

An end-to-end framework for reactivity in heterogeneous catalysis (open access)

Fig. 1: CARE workflow from network generation to reactivity analysis.

Copper superatom nanocluster converts CO2 into simple chemicals and fuels

Amazing stuff! Good news! I don't think we have enough CO2 in the atmosphere! Just kidding!

Remember, atmospheric CO2 is mostly alarmism and hysteria!

"A rare copper nanocluster has been synthesised that behaves as a ‘superatom’. The Chinese team hopes it will unlock copper’s long-promised potential for sustainable carbon-to-fuel chemistry, turning carbon dioxide into valuable chemicals. ...

designed a protective shell of organic ligands that bind tightly to the cluster, locking the atoms into a stable arrangement. The result is a new cluster, [Cu45H6(C≡CR)18(OAc)15] (or Cu45 for short).

‘It is resistant to heat, oxidation and reduction, as well as acidic and basic conditions,’ ... ‘and survives longer than any other Cu(0)-based cluster known to date.’ Cu45’s ‘ultrastability’ is thanks to its electronic structure, which features a large energy gap that makes it far less prone to oxidation.

The team also tested Cu₄₅ as an electrocatalyst, finding that it converts carbon dioxide into multi-carbon products such as ethylene, ethanol and acetic acid with a high Faradaic efficiency. ..."

From the abstract:

"Atomically coinage metal nanoclusters are highly attractive for various applications including catalysis, photochemistry, and energy conversion. While Cu nanoclusters are low cost, their development has lagged behind that of Au and Ag counterparts due to their inherent instability primarily caused by the low Cu(I)/Cu(0) reduction potential. Therefore, the synthesis of stable Cu(0)-containing nanoclusters remains a formidable challenge.

Herein, we report the first 6-electron superatomic copper nanocluster, [Cu45H6(C≡CR)18(OAc)15] (Cu45). This cluster has remarkable stability, being resistant to thermal, oxidative, reductive, acidic, and basic treatments. Single-crystal X-ray diffraction analysis and time-dependent DFT calculations reveal that the outstanding stability of Cu45 is attributed to its superatomic electronic configuration (1S21P4) and strong copper–ligand interactions.

Furthermore, Cu45 is the first well-defined Cu superatom electrocatalyst used for CO2-to-C2H4 electrocatalysis, which exhibits outstanding performance with a maximum Faradaic efficiency for C2+ products of 81.8% (58% for ethene), surpassing all known copper cluster catalysts.

In situ ATR-SEIRAS and theoretical calculations reveal that Cu45 effectively activates CO2 and promotes C–C coupling, thereby facilitating the formation of C2+ products. This work provides new insights into the design of robust Cu nanoclusters for electrocatalytic applications, enabling their broader application in future research and technology development."

Copper superatom nanocluster converts CO2 into simple chemicals and fuels | Chemistry World

Ultrastable Copper Superatom (no public access)

Space-filling model of the Cu45 superatom

The molecular structure of the Cu45 superatom

Turning polystyrene waste into valuable chemicals like toluene with single-atom catalysts

Good news!

"... Researchers ... recently introduced a new approach to convert polystyrene (PS), a plastic widely used to pack some foods and other products, into toluene, a hydrocarbon that is of value in industrial and manufacturing settings. Their proposed strategy, outlined in a paper ... entails heating polystyrene waste in hydrogen and breaking it down into smaller vapor molecules, a process known as hydro-pyrolysis. ..."

From the abstract:

"Converting plastic waste into valuable products mitigates plastic pollution and lowers the carbon footprint of naphtha-derived aromatics. However, the difficulties of precisely controlling complex multiphase systems and the catalyst inefficiencies hinder process viability.

Here we report a vapour-phase hydrogenolysis strategy catalysed by Ru single atoms on Co3O4 (RuSA/Co3O4), decoupling depolymerization from hydrogenolysis to overcome the toluene yield–selectivity trade-off.

In a pressurized dual-stage fixed-bed reactor, polystyrene undergoes hydropyrolysis at 475 °C, followed by vapour-phase hydrogenolysis at 275 °C (0.4 MPa H2, 2.4 s), yielding toluene with 99% selectivity, 83.5 wt% yield and 1,320 mmol gcat.−1 h−1 rate.

The RuSA/Co3O4 catalyst demonstrates excellent stability, maintaining >99% conversion and selectivity during 100 h continuous operation (turnover number 24,747), and effectively processes diverse real-world polystyrene wastes.

Life-cycle assessment shows a 53% carbon footprint reduction over fossil-based methods, while techno-economic analysis estimates a competitive minimum selling price of US$0.61 kg−1, below the US$1 kg−1 industry benchmark."

Turning plastic waste into valuable chemicals with single-atom catalysts

Breaking the yield–selectivity trade-off in polystyrene waste valorization via tandem depolymerization and hydrogenolysis (no public access)

Solar hydrogen can now be produced efficiently without the scarce metal platinum

Good news! This could be a breakthrough! Photocatalysis without platinum  instead of electrolysis!

However, what are the effects of hydrogen power at large scale on the environment?

I have previously blogged here oft my critical opinion about hydrogen and water! And always remember the Hindenburg disaster of 1937!

"A research team led by Chalmers University of Technology, Sweden, have presented a new way to produce hydrogen gas without the scarce and expensive metal platinum. Using sunlight, water and tiny particles of electrically conductive plastic, the researchers show how the hydrogen can be produced efficiently, sustainably and at low cost. ...

In a new study, published in the scientific journal Advanced Materials, a research team led by Professor Ergang Wang at Chalmers, show how solar energy can be used to produce hydrogen gas efficiently – and completely without platinum.  ...

The key to the new approach lies in advanced materials design of the electrically conductive plastic used in the process. This type of plastic, known as conjugated polymers, absorbs light efficiently, but is typically less compatible with water.

By adjusting the material properties at the molecular level, the researchers made the material much more water compatible.

“We also developed a way to form the plastic into nanoparticles that can enhance the interactions with water and boost the light-to-hydrogen process. The improvement comes from more loosely packed, more hydrophilic polymer chains inside the particles” ..."

From the abstract:

"While the interest in hydrogen photocatalysis from organic semiconductors is rapidly growing, there is a necessity to achieve hydrogen production without platinum (Pt), considering its price, availability and toxicity.

In this work, this is demonstrated that high hydrogen evolution reaction (HER) efficiencies can be achieved without the use of Pt. A series of low-cost conjugated polymers are designed around the dibenzothiophene-S,S-sulfoxide (BTSO) unit, and self-assembled as nanoparticles in water via the nanoprecipitation technique.

This is highlighted that how side chain engineering, nanoparticle morphology and pH influence the hydrogen evolution rate.

Optoelectronic properties are improved through a Donor-Acceptor structure, resulting in an unprecedented hydrogen evolution reaction rate of 209 mmol g−1 h−1 in the absence of Pt.

A clear correlation between high efficiencies and number of BTSO units within the polymer backbone can be established. The design rules pioneer the design of future organic materials is presented for a cost-efficient and sustainable hydrogen photocatalysis."

Solar hydrogen can now be produced efficiently without the scarce metal platinum | Chalmers

Highly Efficient Platinum-Free Photocatalytic Hydrogen Evolution From Low-cost Conjugated Polymer Nanoparticles (open access, published in July 2025)

Credits: Wasserstoff aus Sonnenlicht: Gelingt so der große Durchbruch?

In the reactor at the chemistry laboratory at Chalmers, bubbles of hydrogen gas can be easily seen with the naked eye as they form – showing that photocatalysis is happening efficiently.

Fig. 1 Reported Hydrogen Evolution Reaction (HER) rates in the literature, updated in January 2025, and compared to the HER rate achieved in this work.

Fig. 2 a) Chemical structure of the polymers synthesized through a Suzuki-Miyaura cross-coupling polycondensation, highlighting in blue the electron accepting BTSO unit and in pink the electron donating thiophene unit.

b) Schematic representation of the nanoprecipitation mechanism, resulting in water-dispersed nanoparticles.

c) Absorption,

d) nanoparticle size distribution and e) hydrogen evolution of PFBTSO and PFgBTSO nanoparticles dispersed in water. Absorption spectra intensities were normalised at 405 nm. Photocatalytic experiments were performed using 0.25 mg of polymer nanoparticles in 10 mL of water, 0.1 M of ascorbic acid, no additional Pt cocatalyst and under 1 sun.

New, cheap catalyst improves mixed plastic waste recycling efficiency with no sorting

Good news! This could be a breakthrough!

"Researchers ... might have a way to largely skip sorting plastic. Their process uses an inexpensive catalyst that selectively breaks down the most common single-use kind of plastics into liquid oils and waxes that can be upcycled into lubricants and fuels. ...

The polyolefins ... are what trash bags, plastic wrap, squeeze bottles, and other disposable single-use packaging are made of. It's estimated that more than 220 million tons of polyolefin products are manufactured annually around the world – but only 1% to 10% of it is recycled globally, in part because this material is awfully hard to break down. ...

With its single-site design, the nickel-based catalyst preferentially cuts carbon-carbon bonds when used in plastic recycling processes. As such, it selectively breaks down only branched polyolefins for easier upcycling. It's especially remarkable because ... "polyolefins don’t have any weak links. Every bond is incredibly strong and chemically unreactive.”

This catalyst also happens to operate at a lower temperature and require less hydrogen gas to act on plastics. It also remains stable when exposed to polyvinyl chloride (PVC), a compound commonly found in pipes and flooring that contaminates plastics in the recycling process to the point where the entire batch becomes unusable and must be discarded. In fact, the inclusion of PVC actually accelerated the catalyst-driven process further. ..."

"... “Compared to other nickel-based catalysts, our process uses a single-site catalyst that operates at a temperature 100 degrees lower and at half the hydrogen gas pressure,” ... “We also use 10 times less catalyst loading, and our activity is 10 times greater. So, we are winning across all categories.” ...

Amazingly, not only did ... catalyst withstand PVC contamination, PVC actually accelerated its activity. Even when the total weight of the waste mixture is made up of 25% PVC, the scientists found their catalyst still worked with improved performance. This unexpected result suggests the team’s method might overcome one of the biggest hurdles in mixed plastic recycling — breaking down waste currently deemed “unrecyclable” due to PVC contamination. ..."

From the abstract:

"Current methods of processing accumulated polyolefin waste typically require harsh conditions, precious metals or high metal loadings to achieve appreciable activities.

Here we examined supported, single-site organonickel catalysts for polyolefin upcycling. Chemisorption of Ni(COD)2 (COD, 1,5-cyclooctadiene) onto Brønsted acidic sulfated alumina (AlS) yields a highly electrophilic Ni(I) precatalyst, AlS/Ni(COD)2, which is converted under H2 to the active AlS/NiIIH catalyst.

This single-site system exhibits unique hydrogenolysis selectivity that favours cleaving branched polyolefin C–C linkages, enabling the hydrogenolytic separation of polyethylene and isotactic polypropylene (iPP) mixtures.

Moreover, AlS/NiIIH remains highly selective and active for hydrogenolysis of iPP admixed with polyvinyl chloride, and the spent catalyst can be repeatedly regenerated by AlEt3 treatment.

Experimental mechanistic analysis and density functional theory modelling reveal a turnover-limiting C–C scission pathway featuring β-alkyl transfer and strong olefin binding. These results highlight the potential of nickel-based systems for the selective upcycling of complex plastic waste streams."

New catalyst improves plastic recycling efficiency

No-sort plastic recycling is near (original news release) "New catalyst could make mixed plastic recycling a reality"

Stable single-site organonickel catalyst preferentially hydrogenolyses branched polyolefin C–C bonds (no public access)

Scientists catch catalysis in action at the atomic level for the first time

Amazing stuff!

"The reaction involves the removal of hydrogen atoms from alcohol molecules. In amazing new videos, individual atoms are seen moving and shaking during the reaction. ..."

From the highlights and abstract:

"The bigger picture

Catalysis enormously benefits today’s society—from energy production, fertilizers, advanced materials, and fine chemicals to pharmaceuticals—where heterogeneous catalysts comprise a pivotal 85% of industrial processes.

However, unraveling the atomistic intricacies of these processes remains challenging yet essential for creating greener, more atom-efficient next-generation catalysts. Here, we focus on studying the mechanism of sustainable H2 production via catalytic alcohol dehydrogenation over a single-site carbon-bound MoO2 catalytic center. We seek to visualize species along the mechanistic pathway through atomic-resolution transmission electron microscopy. Combining those results with data from other complementary experimental and theoretical characterization tools unveils the relationship of key intermediates along the complex dehydrogenation reaction pathway and provides essential clues for enhancing catalytic activity.

Highlights

• Organic intermediate dynamics are observed on the catalyst surface

• EXAFS, XANES, XPS, DFT, and kinetic analyses support the findings

• A new reaction pathway is proposed from experiments and theory

Summary

Heterogeneous catalysts dominate the chemical industry but, unlike homogeneous catalysts, typically feature diverse, incompletely defined active sites. Thus, describing their structure-activity relationships remains challenging.

In contrast, molecularly defined single-site heterogeneous catalysts (SSHCs) are poised to address these challenges and provide new avenues for catalysis research and development.

The present study explores eco-friendly H2 production mediated by discrete MoO2 sites supported on carbon nanohorns (CNHs) and active for alcohol dehydrogenation.

Although informative, detailed extended X-ray absorption fine structure (EXAFS), X-ray absorption near-edge structure (XANES), X-ray photoelectron spectroscopy (XPS,) kinetic measurements, and density functional theory (DFT) analysis alone cannot provide a full molecular picture of the reaction pathway.

Here, using single-molecule atomic-resolution time-resolved electron microscopy (SMART-EM), we propose the identification of four key catalytic intermediates anchored to CNHs and uncover a new reaction pathway involving alkoxide/hemiacetal equilibration and acetal oligomerization. These intermediates are inferred through a combination of theory and SMART-EM, showcasing the potential of SMART-EM as a complementary tool for exploring mechanistic hypotheses in catalysis."

WATCH: Scientists catch catalysis in action at the atomic level for the first time

Watch a live catalytic event in real time (original news release) "New observations could lead to more efficient catalysts for green hydrogen production"

Atomic-resolution imaging as a mechanistic tool for studying single-site heterogeneous catalysis (no public access)

Atomic-Resolution Cinematography of Catalytic Intermediates over a Single-Site Heterogeneous Catalyst (preprint, open access)

Graphical abstract

New catalyst makes production of industrial chemical ethylene oxide significantly greener

Good news! However, this is a theoretical study!

"Scientists have discovered a potentially greener way to produce a crucial industrial chemical used to make many everyday products from plastics and textiles to antifreeze and disinfectants ..."

"... In a new study in the journal Science, researchers have demonstrated that adding small amounts of nickel to silver catalysts can do away with chlorine while maintaining  production efficiencies for industrial-scale production.

Ethylene oxide (C2H4O) is created through the reaction of ethylene (C2H4) and oxygen in the presence of a silver catalyst, which reduces the energy required for the process. ...

The new study found that adding just one atom of nickel for every 200 silver atoms in the catalyst resulted in the same 25% improvement. ..."

"... The team has submitted international patents for its discovery and is in discussions with a major commercial producer about implementing the technology in existing manufacturing facilities. ..."

From the editor's summary and abstract:

"Editor’s summary

Traces of nickel can increase the selectivity of supported silver ethylene epoxidation catalysts to levels comparable to that of added alkyl chloride promoters. Theoretical studies ... showed that nickel dopants on silver could activate molecular oxygen, and surface science experiments showed that nickel could stabilize nucleophilic oxygen that would otherwise react unselectively. Parts per million addition of nickel enhanced selectivity by 25%, and added chlorine could also boost the effect of nickel by an additional 10%. ..."

Abstract

Over the last 80 years, chlorine (Cl) has been the primary promoter of the ethylene epoxidation reaction valued at ~40 billion USD per year, providing a ~25% selectivity increase over unpromoted silver (Ag) (~55%). Promoters such as cesium, rhenium, and molybdenum each add a few percent of selectivity enhancements to achieve 90% overall, but their codependence on Cl makes optimizing and understanding their function complex.

We took a theory-guided, single-atom alloy approach to identify nickel (Ni) as a dopant in Ag that can facilitate selective oxidation by activating molecular oxygen (O2) without binding oxygen (O) too strongly. Surface science experiments confirmed the facile adsorption/desorption of O2 on NiAg, as well as demonstrating that Ni serves to stabilize unselective nucleophilic oxygen. Supported Ag catalyst studies revealed that the addition of Ni in a 1:200 Ni to Ag atomic ratio provides a ~25% selectivity increase without the need for Cl co-flow and acts cooperatively with Cl, resulting in a further 10% initial increase in selectivity.

New catalyst makes production of industrial chemical greener

Engineers find greener path to making key industrial chemical (original news release)

Nickel promotes selective ethylene epoxidation on silver (no public access)

Light-powered catalysts destroy forever chemicals aka PFAS

So much for the daily alarmism and hysteria about so called forever chemicals!

Human ingenuity can easily handle it!

By the way, how dangerous are these PFAS actually? We are to believe these must be killer chemicals according to the alarmism and hysteria. I have my doubts.

"... Today [11/20/2024], two groups report in Nature the discovery of catalysts that could offer a cheaper way to clean up the chemicals. When energized by light, the catalysts break down a wide range of PFAS compounds at low temperatures and ambient pressures. ..."

Light-powered catalysts destroy ‘forever chemicals’ | Science | AAAS

First ever video of nanoscale direct visualization of hydrogen and oxygen atoms forming water using Palladium as catalyst

Good news! Amazing stuff! This could be a game changer!

"... A rare element called palladium is known to be a good catalyst for converting gaseous hydrogen and oxygen into water, but exactly how it works remains poorly understood. So for the new study, researchers ... used a recently developed technique to watch in precise, molecular detail what was happening.

They placed samples of palladium into honeycomb-shaped nanoreactors, encased in an ultra-thin membrane of glass. Then, the gases were introduced. The whole show was viewed using high-vacuum transmission electron microscopes. ...

With further experiments, the team found the optimal method for using palladium to produce water. Adding hydrogen first, followed by oxygen, led to the fastest reaction rate. The hydrogen atoms would squeeze into the metal, then come back out when oxygen was added to produce water on the palladium’s surface. ..."

From the significance and abstract:

"Significance

Unraveling the reaction kinetics of Pd-catalyzed, water-forming hydrogen oxidation under various gas conditions has posed a considerable experimental challenge. In this study, we achieve nanoscale direct visualization of water formation from this reaction using gas cell transmission electron microscopy. We disentangle the intricate interplay between adsorption, atomic diffusion, and concurrent phase transformation of catalyst. The observed differences in water generation rates with varying gas supply sequences, corroborated by electron diffraction analysis, indicate that the rate of Pd-catalyzed hydrogen oxidation is limited by precursors adsorption. This understanding enables identifying the optimal catalytic reaction condition, holding substantial implications for applications in water generation. Furthermore, our findings advocate exploration of analogous mechanisms in other metal-catalyzed reactions.

Abstract

Palladium (Pd) catalysts have been extensively studied for the direct synthesis of H2O through the hydrogen oxidation reaction at ambient conditions. This heterogeneous catalytic reaction not only holds considerable practical significance but also serves as a classical model for investigating fundamental mechanisms, including adsorption and reactions between adsorbates. Nonetheless, the governing mechanisms and kinetics of its intermediate reaction stages under varying gas conditions remain elusive. This is attributed to the intricate interplay between adsorption, atomic diffusion, and concurrent phase transformation of catalyst. Herein, the Pd-catalyzed, water-forming hydrogen oxidation is studied in situ, to investigate intermediate reaction stages via gas cell transmission electron microscopy. The dynamic behaviors of water generation, associated with reversible palladium hydride formation, are captured in real time with a nanoscale spatial resolution. Our findings suggest that the hydrogen oxidation rate catalyzed by Pd is significantly affected by the sequence in which gases are introduced. Through direct evidence of electron diffraction and density functional theory calculation, we demonstrate that the hydrogen oxidation rate is limited by precursors’ adsorption. These nanoscale insights help identify the optimal reaction conditions for Pd-catalyzed hydrogen oxidation, which has substantial implications for water production technologies. The developed understanding also advocates a broader exploration of analogous mechanisms in other metal-catalyzed reactions."

Watch: First nanoscale video of hydrogen and oxygen atoms forming water

Watch water form out of thin air "For first time, researchers witnessed formation of tiny water bubbles in real time"

Unraveling the adsorption-limited hydrogen oxidation reaction at palladium surface via in situ electron microscopy (no public access)

New technology provides electrifying insights into how catalysts work at the atomic level

Good news! Amazing stuff!

"... The scientists have developed a cell—a small enclosed chamber that can hold all the components of an electrochemical reaction—that can be paired with transmission electron microscopy (TEM) to generate precise views of a reaction at an atomic scale. Better yet, their device, which they call a polymer liquid cell (PLC), can be frozen to stop the reaction at specific timepoints, so scientists can observe composition changes at each stage of a reaction with other characterization tools. ..."

From the abstract:

"Electrified solid–liquid interfaces (ESLIs) play a key role in various electrochemical processes relevant to energy, biology and geochemistry. The electron and mass transport at the electrified interfaces may result in structural modifications that markedly influence the reaction pathways. For example, electrocatalyst surface restructuring during reactions can substantially affect the catalysis mechanisms and reaction products. Despite its importance, direct probing the atomic dynamics of solid–liquid interfaces under electric biasing is challenging owing to the nature of being buried in liquid electrolytes and the limited spatial resolution of current techniques for in situ imaging through liquids. Here, with our development of advanced polymer electrochemical liquid cells for transmission electron microscopy (TEM), we are able to directly monitor the atomic dynamics of ESLIs during copper (Cu)-catalysed CO2 electroreduction reactions (CO2ERs). Our observation reveals a fluctuating liquid-like amorphous interphase. It undergoes reversible crystalline–amorphous structural transformations and flows along the electrified Cu surface, thus mediating the crystalline Cu surface restructuring and mass loss through the interphase layer. The combination of real-time observation and theoretical calculations unveils an amorphization-mediated restructuring mechanism resulting from charge-activated surface reactions with the electrolyte. Our results open many opportunities to explore the atomic dynamics and its impact in broad systems involving ESLIs by taking advantage of the in situ imaging capability."

New technology provides electrifying insights into how catalysts work at the atomic level

New Technology Provides Electrifying Insights into How Catalysts Work at the Atomic Level (original news release) An approach developed by materials scientists is already yielding discoveries that could improve the efficiency and durability of metallic catalysts used in a variety of processes

Atomic dynamics of electrified solid–liquid interfaces in liquid-cell TEM (no public access)

Researchers look at the results of measurements obtained using their new technology, which pairs with powerful microscopes at Berkeley Lab's National Center for Electron Microscopy. 

A schematic showing the different components of the polymer liquid cell (PLC) that the team developed.

With just a little electricity, MIT researchers boost common catalytic reactions

Good news! Could be a breakthrough!

"A simple technique that uses small amounts of energy could boost the efficiency of some key chemical processing reactions, by up to a factor of 100,000, MIT researchers report. These reactions are at the heart of petrochemical processing, pharmaceutical manufacturing, and many other industrial chemical processes. ...
The dramatically increased rates reported in the new study “have never been observed for reactions that don’t involve oxidation or reduction,” ...

The non-redox chemical reactions studied by the MIT team are catalyzed by acids. “... first type of catalyst you learn about is an acid catalyst  ... they’re super important in everything from processing petrochemical feedstocks to making commodity chemicals to doing transformations in pharmaceutical products. The list goes on and on.” ...

While there has typically been little interaction between electrochemical and thermochemical catalysis researchers ... “this study shows the community that there’s really a blurring of the line between the two, and that there is a huge opportunity in cross-fertilization between these two communities.” ..."

From the editor's summary and abstract:

"Editor’s summary

Conventional Brønsted acids are among the oldest catalysts and are still the most effective. Because they operate by simple proton transfer, however, their accelerating effects are not easily amenable to improvement through structural modification. ... report that the application of an electrochemical potential can tilt protonation pre-equilibria and thereby accelerate an acid-catalyzed alcohol dehydration by up to 100,000-fold. The strategy was also effective in accelerating a Friedel-Crafts acylation, suggesting that it may have broad applicability to acid-catalyzed chemistry. ...

Abstract

Electric fields play a key role in enzymatic catalysis and can enhance reaction rates by 100,000-fold, but the same rate enhancements have yet to be achieved in thermochemical heterogeneous catalysis. In this work, we probe the influence of catalyst potential and interfacial electric fields on heterogeneous Brønsted acid catalysis. We observed that variations in applied potential of ~380 mV led to a 100,000-fold rate enhancement for 1-methylcyclopentanol dehydration, which was catalyzed by carbon-supported phosphotungstic acid. Mechanistic studies support a model in which the interfacial electrostatic potential drop drives quasi-equilibrated proton transfer to the adsorbed substrate prior to rate-limiting C–O bond cleavage. Large increases in rate with potential were also observed for the same reaction catalyzed by Ti/TiOyHx and for the Friedel Crafts acylation of anisole with acetic anhydride by carbon-supported phosphotungstic acid."

With just a little electricity, MIT researchers boost common catalytic reactions | MIT News | Massachusetts Institute of Technology Applying a small voltage to a catalyst can increase the rates of reactions used in petrochemical processing, pharmaceutical manufacture, and many other processes.

Electrically driven proton transfer promotes Brønsted acid catalysis by orders of magnitude (no public access)

New atomic-scale understanding of catalysis could unlock massive energy savings

Good news! This might be early stage research!

"In an advance they consider a breakthrough in computational chemistry research ... engineers have developed model of how catalytic reactions work at the atomic scale. This understanding could allow engineers and chemists to develop more efficient catalysts and tune industrial processes—potentially with enormous energy savings, given that 90% of the products we encounter in our lives are produced, at least partially, via catalysis. ...
In fact, just three catalytic reactions—steam-methane reforming to produce hydrogen, ammonia synthesis to produce fertilizer, and methanol synthesis—use close to 10% of the world's energy. ...
“If you decrease the temperatures at which you have to run these reactions by only a few degrees, there will be an enormous decrease in the energy demand that we face as humanity today,” ...
In their research, ... engineers develop and use powerful modeling techniques to simulate catalytic reactions at the atomic scale. For this study, they looked at reactions involving transition metal catalysts in nanoparticle form, which include elements like platinum, palladium, rhodium, copper, nickel, and others ...
It is also relevant to understanding other important phenomena, including corrosion and tribology, or the interaction of surfaces in motion. ..."

From the abstract:

"Adopting low-index single-crystal surfaces as models for metal nanoparticle catalysts has been questioned by the experimental findings of adsorbate-induced formation of subnanometer clusters on several single-crystal surfaces. We used density functional theory calculations to elucidate the conditions that lead to cluster formation and show how adatom formation energies enable efficient screening of the conditions required for adsorbate-induced cluster formation. We studied a combination of eight face-centered cubic transition metals and 18 common surface intermediates and identified systems relevant to catalytic reactions, such as carbon monoxide (CO) oxidation and ammonia (NH3) oxidation. We used kinetic Monte Carlo simulations to elucidate the CO-induced cluster formation process on a copper surface. Scanning tunneling microscopy of CO on a nickel (111) surface that contains steps and dislocations points to the structure sensitivity of this phenomenon. Metal-metal bond breaking that leads to the evolution of catalyst structures under realistic reaction conditions occurs much more broadly than previously thought."

New atomic-scale understanding of catalysis could unlock massive energy savings

Formation of active sites on transition metals through reaction-driven migration of surface atoms (no public access)

Credits: New atomic-scale understanding of catalysis could unlock massive energy savings

Purifying water with just a few atoms

Amazing stuff! Water purification at the level of single atoms!

This research seems to describe a further and promising advancement of nanocatalysts.

Besides purification, I bet something similar can also be applied to desalination! Desalination is salvation!

"Due to their considerable efficiency, catalysts made of just a few atoms show great promise in the field of water treatment. In a new study, researchers looked into how to optimize the performance of these catalysts and make them viable for practical use. ...
a system with a catalyst using an ensemble of palladium atoms, designed to reduce the carcinogen bromate in water. They introduced the non-metal elements sulfur, nitrogen, and boron to the surrounds of atom ensembles. The overall results suggested an improvement in the system’s catalytic performance. ..."

From the significance and abstract:

"Significance

Substrate-anchored, single-atom catalysts (SACs) have emerged as a promising alternative to conventional nanocatalysts for various catalytic processes. The catalytic performance of SACs can be controlled by various synthetic strategies, including the manipulation of substrate atoms surrounding metal sites. This study examines whether the coordination environment (CE) of the palladium metal ensemble, a newly identified small-clustered structure with CE resembling that of SAC, can also be tuned by doping nonmetal elements onto the substrate. The results demonstrate that such CE manipulation could decrease the activation energy of the rate-limiting step and achieve efficient H2 dissociation for several important reductive catalytic schemes, establishing a new strategy to effectively engineer metal ensemble catalysts.

Abstract

Atomic dispersion of metal catalysts on a substrate accounts for the increased atomic efficiency of single-atom catalysts (SACs) in various catalytic schemes compared to the nanoparticle counterparts. However, lacking neighboring metal sites has been shown to deteriorate the catalytic performance of SACs in a few industrially important reactions, such as dehalogenation, CO oxidation, and hydrogenation. Metal ensemble catalysts (Mn), an extended concept to SACs, have emerged as a promising alternative to overcome such limitation. Inspired by the fact that the performance of fully isolated SACs can be enhanced by tailoring their coordination environment (CE), we here evaluate whether the CE of Mn can also be manipulated in order to enhance their catalytic activity. We synthesized a set of Pd ensembles (Pdn) on doped graphene supports (Pdn/X-graphene where X = O, S, B, and N). We found that introducing S and N onto oxidized graphene modifies the first shell of Pdn converting Pd–O to Pd–S and Pd–N, respectively. We further found that the B dopant significantly affected the electronic structure of Pdn by serving as an electron donor in the second shell. We examined the performance of Pdn/X-graphene toward selective reductive catalysis, such as bromate reduction, brominated organic hydrogenation, and aqueous-phase CO2 reduction. We observed that Pdn/N-graphene exhibited superior performance by lowering the activation energy of the rate-limiting step, i.e., H2 dissociation into atomic hydrogen. The results collectively suggest controlling the CE of SACs in an ensemble configuration is a viable strategy to optimize and enhance their catalytic performance."

Purifying water with just a few atoms | Yale School of Engineering & Applied Science

Enhancing the activity of Pd ensembles on graphene by manipulating coordination environment (no public access)

3D-printed single-atom catalysts brings industry use closer

Amazing stuff! This could have some huge potential!

"A simple protocol has been developed to make single-atom catalysts using 3D printing. The researchers believe the procedure, which removes the need for a variety of complex and expensive synthetic processes, could prove scalable and therefore allow industry to benefit from the advantages of single-atom catalysis.
In single-atom catalysts, the catalyst is atomically dispersed – usually on a solid substrate. This offers several advantages over traditional heterogeneous catalysts, such as greater atom economy and the potential to tailor reaction pathways with tailored coordination environments.  ...
employed iron acetylacetonate and natural polymers to form an ink. They then deposited this on substrates in a variety of different patterns before freeze-drying it to remove excess water. Finally, they heated the printed scaffold to 700°C. When they examined the resulting structure using multiple characterisation methods, they confirmed that the metal atoms were atomically dispersed on carbon substrates, with no evidence of cluster formation. Moreover, the material was an excellent electrocatalyst for the reduction of nitrate to ammonia. ..."

From the abstract:

"A mass production route to single-atom catalysts (SACs) is crucial for their end use application. To date, the direct fabrication of SACs via a simple and economic manufacturing route remains a challenge, with current approaches relying on convoluted processes using expensive components. Here, a straightforward and cost-effective three-dimensional (3D) printing approach is developed to fabricate a library of SACs. Despite changing synthetic parameters, including centre transition metal atom, metal loading, coordination environment and spatial geometry, the products show similar atomic dispersion nature of single metal sites, demonstrating the generality of the approach. The 3D-printed SACs exhibited excellent activity and stability in the nitrate reduction reaction. It is expected that this 3D-printing technique can be used as a method for large-scale commercial production of SACs, thus enabling the use of these materials in a broad spectrum of industrial applications."

3D-printed single-atom catalysts brings industry use closer | Research | Chemistry World

A general approach to 3D-printed single-atom catalysts (no public access)

Cheap, sustainable hydrogen: New catalyst is 10 times more efficient than previous sun-powered water-splitting devices. Really!

Good news! If I am not mistaken, the big question is still whether hydrogen generation can scale up to provide energy to hundreds of millions of people and businesses! Will it be affordable and safe to use?

Overpromising and understating is a very common feature of the advocates of so called clean or renewable energy!

And again propaganda and demagoguery is being used by the scientists!

The catalyst needs Indium, a fairly rare element! An efficiency of 9% still sounds quite low and it requires pure water!

"A new kind of solar panel, developed at the University of Michigan, has achieved 9% efficiency in converting water into hydrogen and oxygen—mimicking a crucial step in natural photosynthesis. Outdoors, it represents a major leap in the technology, nearly 10 times more efficient than solar water-splitting experiments of its kind. ..."

"... But the biggest benefit is driving down the cost of sustainable hydrogen. This is enabled by shrinking the semiconductor, typically the most expensive part of the device. The team’s self-healing semiconductor withstands concentrated light equivalent to 160 suns. ..."

From the abstract:

"Production of hydrogen fuel from sunlight and water, two of the most abundant natural resources on Earth, offers one of the most promising pathways for carbon neutrality [???]. Some solar hydrogen production approaches, for example, photoelectrochemical water splitting, often require corrosive electrolyte, limiting their performance stability and environmental sustainability. Alternatively, clean hydrogen can be produced directly from sunlight and water by photocatalytic water splitting. The solar-to-hydrogen (STH) efficiency of photocatalytic water splitting, however, has remained very low. Here we have developed a strategy to achieve a high STH efficiency of 9.2 per cent using pure water, concentrated solar light and an indium gallium nitride photocatalyst. The success of this strategy originates from the synergistic effects of promoting forward hydrogen–oxygen evolution and inhibiting the reverse hydrogen–oxygen recombination by operating at an optimal reaction temperature (about 70 degrees Celsius), which can be directly achieved by harvesting the previously wasted infrared light in sunlight. Moreover, this temperature-dependent strategy also leads to an STH efficiency of about 7 per cent from widely available tap water and sea water and an STH efficiency of 6.2 per cent in a large-scale photocatalytic water-splitting system with a natural solar light capacity of 257 watts. Our study offers a practical approach to produce hydrogen fuel efficiently from natural solar light and water, overcoming the efficiency bottleneck of solar hydrogen production."

Cheap, sustainable hydrogen: New catalyst is 10 times more efficient than previous sun-powered water-splitting devices

Cheap, sustainable hydrogen through solar power Withstanding high temperatures and the light of 160 suns, a new catalyst is ten times more efficient than previous sun-powered water-splitting devices of its kind.

Cheap, sustainable hydrogen through solar power

Solar-to-hydrogen efficiency of more than 9% in photocatalytic water splitting (no public access)

A close-up of the panel with the semiconductor catalyst and water inside

Revolutionary photocatalyst for green hydrogen and ammonia

Very good news! This could be an fundamental breakthrough and game changer! Ammonia as storage for hydrogen. Photocatalytics could become a new powerful chemical method if it is able to scale up. Apparently, there is already a company trying to commercialize this kind of photocatalytics.

"A fundamental breakthrough in chemistry promises to unlock ammonia as a clean fuel, and it could help decarbonize the entire chemical industry in the process. Rice University researchers have created a small, LED-powered device that converts ammonia to hydrogen on the fly. It uses a light-driven catalyst that's as efficient as expensive thermal catalysts that need thousand-degree temperatures to operate, and it's made from cheap, abundant copper and iron. And it's only the beginning of a technology that could radically reduce costs and energy use in industrial chemistry.
Hydrogen is a very promising clean fuel that can be burned, or converted directly into electricity through a fuel cell. It's both expensive and difficult to handle, though, since it's a super-lightweight gas that needs to be compressed to 700 atmospheres, or else cryogenically cooled within sight of absolute zero to reach its liquid state.
Ammonia is famously a better hydrogen carrier than hydrogen gas itself; each of its nitrogen atoms binds three hydrogen atoms, and while it's caustic and extremely hazardous in high concentrations, it's a stable liquid at atmospheric temperatures and pressures, and its widespread use in many industries means people have plenty of experience handling it safely under a wide range of conditions. ...
It comes down to photocatalytics; this team has been working for more than 30 years to develop its "antenna-reactor" plasmonic photocatalysts. These are nanoparticles of a catalyst, dotted with little clumps of an "antenna" material designed to increase the catalyst's ability to absorb light. Properly tuned, these antenna-reactor particles take in energy from ambient light – be it sunlight, or light from low-energy LEDs – and kick out short-lived "hot electrons" with enough energy to start an efficient chemical reaction even at ambient temperatures.
This ammonia-splitting photocatalyst uses iron as its reactor, and copper as its light-collecting antenna – both cheap and abundant metals, as opposed to the typical copper-ruthenium thermal catalysts used today. ..."

"Harnessing iron for photocatalysis

Good catalysts bind substrates at intermediate strengths so that neither reactant binding nor product desorption limits the reaction. Platinum group metals often meet this criterion for many reactions and cannot be replaced with cheaper metals such as iron, which often oxidize under reaction conditions. Yuan et al. demonstrate ammonia decomposition to liberate hydrogen with a copper-iron photocatalyst in which plasmons excited in copper generate hot electrons that react with ammonia bound to iron. Iron is not a good thermal catalyst for this reaction, but photoinduced oxygen desorption makes it competitive with a similar copper–ruthenium photocatalyst and with ruthenium thermal catalysts. This reaction, which is driven with light-emitting diodes, may be competitive with thermal catalysts used in this hydrogen carrier system."

From the abstract:

"Catalysts based on platinum group metals have been a major focus of the chemical industry for decades. We show that plasmonic photocatalysis can transform a thermally unreactive, earth-abundant transition metal into a catalytically active site under illumination. Fe active sites in a Cu-Fe antenna-reactor complex achieve efficiencies very similar to Ru for the photocatalytic decomposition of ammonia under ultrafast pulsed illumination. When illuminated with light-emitting diodes rather than lasers, the photocatalytic efficiencies remain comparable, even when the scale of reaction increases by nearly three orders of magnitude. This result demonstrates the potential for highly efficient, electrically driven production of hydrogen from an ammonia carrier with earth-abundant transition metals."

Revolutionary photocatalyst is huge news for green hydrogen and ammonia

Rice’s ‘antenna-reactor’ catalysts offer best of both worlds (2016) In a find that could transform some of the world’s most energy-intensive manufacturing processes, researchers at Rice University’s Laboratory for Nanophotonics have unveiled a new method for uniting light-capturing photonic nanomaterials and high-efficiency metal catalysts.

Rice lab’s catalyst could be key for hydrogen economy Inexpensive catalyst uses energy from light to turn ammonia into hydrogen fuel

Earth-abundant photocatalyst for H2 generation from NH3 with light-emitting diode illumination (no public access)

A reaction cell (left) and the photocatalytic platform (right) used on tests of copper-iron plasmonic photocatalysts for hydrogen production from ammonia at Syzygy Plasmonics in Houston. All reaction energy for the catalysis came from LEDs that produced light with a wavelength of 470 nanometers

Counting charge on a single nanoparticle in catalysis

Amazing stuff!

"Researchers in Japan have developed a way to count the charge on a single nanoparticle. The technique is accurate down to a single electron, and could offer new insights into fundamental aspects of heterogeneous catalysis.

Many heterogeneous catalysts are composed of metal nanoparticles supported on a metal oxide surface. But interactions between the particle and the support structure can affect the material’s catalytic properties, for example charge transfer from the support to the nanoparticle can alter the way in which substrate molecules interact with the catalyst. ..."

From the abstract:

"A goal in the characterization of supported metal catalysts is to achieve particle-by-particle analysis of the charge state strongly correlated with the catalytic activity. Here, we demonstrate the direct identification of the charge state of individual platinum nanoparticles (NPs) supported on titanium dioxide using ultrahigh sensitivity and precision electron holography. Sophisticated phase-shift analysis for the part of the NPs protruding into the vacuum visualized slight potential changes around individual platinum NPs. The analysis revealed the number (only one to six electrons) and sense (positive or negative) of the charge per platinum NP. The underlying mechanism of platinum charging is explained by the work function differences between platinum and titanium dioxide (depending on the orientation relationship and lattice distortion) and by first-principles calculations in terms of the charge transfer processes."

Counting charge on a single nanoparticle | Research | Chemistry World Electron holography enables new insights into catalytic particles

Counting charges per metal nanoparticle (no public access) Charges on a metal nanoparticle are measured with precision by electron holography

Direct identification of the charge state in a single platinum nanoparticle on titanium oxide (no public access)

Designer catalyst with enzyme-like cavity splits water almost as fast as plants

Good news! Efficient replication of photosynthesis is one of those holy grails! It could e.g. become a new source of energy supply!

"Using molecular design, researchers have developed a synthetic water oxidation catalyst with an enzyme-like cavity to speed up the reaction. This unusual catalytic system achieves the challenging oxidative water-splitting reaction at a comparable rate to the photosystems found in photosynthesis.
Water oxidation is a key step in photosynthesis and involves splitting two water molecules into molecular oxygen and protons using solar energy. While this process is crucial in nature to sustain life, the ability to cheaply reproduce this reaction could help meet humanity’s energy needs by creating a steady stream of oxygen and hydrogen. Synthetic mimics of the natural oxygen evolving complex are known, but generally suffer from low catalytic activity or short lifetimes. ..."

Unfortunately, the following abstract is extremely technical!

From the abstract:

"Inspired by the proficiency of natural enzymes, mimicking of nanoenvironments for precise substrate preorganization is a promising strategy in catalyst design. However, artificial examples of enzyme-like activation of H2O molecules for the challenging oxidative water splitting reaction are hardly explored. Here, we introduce a mononuclear Ru(bda) complex (M1, bda = 2,2′-bipyridine-6,6′-dicarboxylate) equipped with a bipyridine-functionalized ligand to preorganize H2O molecules in front of the metal centre as in enzymatic clefts. The confined pocket of M1 accelerates chemically driven water oxidation at pH 1 by facilitating a water nucleophilic attack pathway with a remarkable turnover frequency of 140 s−1 that is comparable to the oxygen-evolving complex of photosystem II. Single crystal X-ray analysis of M1 under catalytic conditions allowed the observation of a seventh H2O ligand directly coordinated to a RuIII centre. Another H2O substrate is preorganized via a well-defined hydrogen-bonding network for the crucial O–O bond formation by nucleophilic attack."

Designer catalyst with enzyme-like cavity splits water almost as fast as plants | Research | Chemistry World

Enzyme-like water preorganization in a synthetic molecular cleft for homogeneous water oxidation catalysis (no public access)

AI-engineered enzyme eats entire plastic containers

Good news! Effective plastic waste management is coming! Once more, human ingenuity at its best! And this is only the beginning!

Dismiss most of the alarmism and hysteria about plastic! Plastic is one of the greatest inventions of modern times! Plastophobia is a serious disease, please get treated immediately! 😄

"A plastic-degrading enzyme enhanced by amino acid changes designed by a machine-learning algorithm can depolymerise polyethylene terephthalate (PET) at least twice as fast and at lower temperatures than the next best engineered enzyme. ...

Six years ago scientists sifting through debris of a plastic bottle recycling plant discovered a bacterium that can degrade PET. The organism has two enzymes that hydrolyse the polymer first into mono-(2-hydroxyethyl) terephthalate and then into ethylene glycol and terephthalic acid to use as an energy source.

One enzyme in particular, PETase, has become the target of protein engineering efforts to make it stable at higher temperatures and boost its catalytic activity. ...
Out of the millions of possible combinations, the researchers zeroed in on three suggested amino acid substitutions. Combined with two modifications from a previous PETase engineering effort, they designed an enzyme that is ‘highly, highly active, especially at lower temperatures, compared to anything else that’s out there’ ..."

From the abstract:

"Plastic waste poses an ecological challenge and enzymatic degradation offers one, potentially green and scalable, route for polyesters waste recycling. Poly(ethylene terephthalate) (PET) accounts for 12% of global solid waste, and a circular carbon economy for PET is theoretically attainable through rapid enzymatic depolymerization followed by repolymerization or conversion/valorization into other products. Application of PET hydrolases, however, has been hampered by their lack of robustness to pH and temperature ranges, slow reaction rates and inability to directly use untreated postconsumer plastics. Here, we use a structure-based, machine learning algorithm to engineer a robust and active PET hydrolase. Our mutant and scaffold combination (FAST-PETase: functional, active, stable and tolerant PETase) contains five mutations compared to wild-type PETase (N233K/R224Q/S121E from prediction and D186H/R280A from scaffold) and shows superior PET-hydrolytic activity relative to both wild-type and engineered alternatives between 30 and 50 °C and a range of pH levels. We demonstrate that untreated, postconsumer-PET from 51 different thermoformed products can all be almost completely degraded by FAST-PETase in 1 week. FAST-PETase can also depolymerize untreated, amorphous portions of a commercial water bottle and an entire thermally pretreated water bottle at 50 ºC. Finally, we demonstrate a closed-loop PET recycling process by using FAST-PETase and resynthesizing PET from the recovered monomers. Collectively, our results demonstrate a viable route for enzymatic plastic recycling at the industrial scale."

AI-engineered enzyme eats entire plastic containers | Research | Chemistry World

Machine learning-aided engineering of hydrolases for PET depolymerization

(No public access, link to PDF file)

The engineered enzyme was able to break down an untreated plastic container within 48 hours

A greener, simpler way to create syngas

Good news!

"In the new research, engineers found a more suitable catalyst: copper with a few atoms of the precious metal ruthenium exposed to visible light. Shaped like a tiny bump about 5 nanometers in diameter (a nanometer is one-billionth of a meter) and lying on top of a metal-oxide support, the new catalyst enables a chemical reaction that selectively produces syngas from the two greenhouse gases using visible light to drive the reaction, without requiring any additional thermal energy input. "

A greener, simpler way to create syngas | UCLA: The key is a new catalyst: copper with a few atoms of the precious metal ruthenium.