Articles

The choice of solvent system has important implications regarding the catalytic upgrading of carbohydrate-containing biomass. Here, Dumesic and co-workers study solvation effects in organic solvent/water mixtures and employ the obtained information to control the rate and selectivity of the acid-catalysed dehydration of fructose.

While methods for arylation of amines are well established, alkylation is a less well-developed process. Here, Hu and co-workers report amine alkylation using redox-active esters, using a combination of photoredox catalysis to generate the active electrophile and copper catalysis for the cross-coupling.

Zeolite-catalysed alkylations of phenolic compounds offer unique possibilities for the valorization of renewable aromatics into substituted arenes. Now, a mechanistic study reveals that the course of the reaction can be dramatically altered by changing the polarity of the solvent, which affects the nature of surface species and the pathway for the generation of the alkylating electrophile.

Understanding structure sensitivity—how the structural morphology of a surface influences a catalytic reaction—is important for rational catalyst design. Here, the synthesis and in-depth characterization of a range of size-defined nickel clusters shows the structure sensitivity of CO₂ hydrogenation, and also identifies two size-dependent reaction pathways.

Nanoconfinement effects are crucial in any process that involves porous materials. Here, the authors present a nanoporous catalyst platform that enables these effects to be studied in situ at the single-molecule and single-particle level with turnover resolution.

Ammonia synthesis is an energy-intensive process due to the high activation barrier for N₂ dissociation. Here, Hosono and co-workers show that the intermetallic compound LaCoSi can lower the energy requirement for N₂ activation and shift the rate-determining step of the process to NH _x formation under mild conditions.

Bifunctional heterogeneous catalysts are usually prepared by dispersion of a metal on an acidic or basic support. Now a method has been developed to post-functionalize a catalyst and introduce tunable acidity by coating an organic acid layer on the support, resulting in improved performance as showcased for selected hydrodeoxygenation reactions.

Electrocatalytic reduction of CO₂ to products containing multiple carbon atoms is useful for producing high-value chemicals and fuels. This work uses theory to predict the preferred copper surface for C–C coupling, and subsequent metal ion cycling to produce the desired facets results in a catalyst that is highly selective for C₂₊ products.

Catalysts that can selectively reduce carbon dioxide to C2+ products are attractive for the generation of more complex and useful chemicals. Here, an electro-redeposited copper catalyst is shown to provide excellent selectivity and high current density for ethylene formation. Detailed characterization and theory link the performance to the catalyst morphology.

The direct synthesis of hydrogen peroxide via oxygen reduction is an attractive alternative to the anthraquinone process. Here, a general trend linking oxygenation of carbon surfaces with electrocatalytic performance in peroxide synthesis is demonstrated, and computational studies provide further insight into the nature of the active sites.

Hydrogenation is one of the most common catalytic processes on both laboratory and industrial scales, and typically is carried out with a noble metal catalyst. Here, the authors show that alkaline earth metal amides are capable of hydrogenating imines under mild conditions.

Lignocellulose is produced in large amounts as waste but offers the potential of cheap, renewable sources of organic compounds. Here, a process is shown that can derive useful products from all the main components of lignocellulose, giving complete conversion and thus enabling integrated catalyst recycling.

The generation of useful chemicals from CO₂ and renewable energy is an attractive—but challenging—endeavour. This work reports on the long-term operation of commercial electrodes for efficient CO₂ reduction, with subsequent fermentation of the syngas product completing the technical photosynthesis of alcohols.

Atomically dispersed metal catalysts are of increasing importance in many catalytic processes, but clear structural identification is challenging. Here, a general synthesis of metal (nickel, iron and cobalt) single-atom catalysts on nitrogen-doped graphene allows the authors to identify a common structure and furthermore correlate structure with electrocatalytic activity.

Peroxygenases can selectively functionalize organic compounds, but are sensitive to the co-substrate H₂O₂. Hollmann and co-workers show that water oxidation catalysts can provide a controlled supply of H₂O₂ to the enzyme in the presence of visible light, allowing efficient oxyfunctionalization without stoichiometric reductants.

During photosynthesis, nature uses an enzyme with a manganese–calcium core for water oxidation. Here, the authors report the synthesis of a stable, water-soluble manganese cluster that acts as a homogeneous water oxidation electrocatalyst, displaying low overpotential and high Faradaic efficiency.

Bioethanol-based alkylation of benzene is a potentially sustainable route to commodity chemicals, but there is little knowledge of the reaction mechanism. Here, Weckhuysen and co-workers study the zeolite catalysed alkylation of benzene with ethanol, identifying the active alkylating agent and experimentally show the presence of a σ-complex intermediate.

Biocatalysis, if selective, offers great potential for the well-controlled release of drugs and other payloads. Here, Minko and co-workers separate enzymes and substrates by loading them onto individual, polymer-coated nanoparticles, and show that a magnetic field switches on the catalytic activity by merging the polymer shells.