Articles

Electrocatalytic hydrogenations of organics allow water to be used as the proton source but are limited by low substrate solubility in aqueous media or by low performance in organic electrolytes. Now, a Pickering emulsion system for electrocatalytic hydrogenation is presented to overcome those issues, where the hydrogenation reaction occurs at the interface between the aqueous and organic phases.

Operando investigation of the CO₂ reduction mechanism at gas diffusion electrodes is a challenging task. Here proton-transfer-reaction time-of-flight mass spectrometry has been deployed to analyse the intermediates and products at copper electrodes in real time.

Activation of inert chemical bonds employing classical photocatalysts usually involves an outer-sphere single electron transfer mechanism. Now, an alternative inner-sphere single electron transfer pathway for the homolytic cleavage of strong C–Cl bonds using gold catalysts is reported.

The Birch reduction is one of the methods of choice to perform the hydrogenation of arenes, although it requires the handling of pyrophoric substances and ammonia at cryogenic temperatures. Here a photocatalytic approach based on boron carbonitride introduces the possibility to hydrogenate (hetero)arenes under mild conditions in water.

Despite great progress in electrocatalytic CO₂ reduction on Cu-based materials, the selectivity for methanol has remained elusive in contrast to thermocatalytic routes. Here, using Cu₂NCN with polarized Cu atoms as the cathode, selectivity of up to 70% for methanol is achieved by favouring cleavage of Cu–O over O–C in the crucial Cu–*O–CH₃ intermediate.

While the promise of low metal utilization has brought single-atom catalysts (SACs) into the spotlight, intrinsic limits in reactivity still restrict their application to a small set of reactions. Here, the authors expand the repertoire of SAC transformations with a nitrogen-doped, carbon-supported, Ru single-atom catalyst that exploits the effect of peripheral N species to promote propane dehydrogenation.

Controlling selectivity during direct unsymmetrical diamination of double bonds is challenging. Now, ambiphilic iminyl and electrophilic amidyl radicals are generated from oxime ester-based bifunctional precursors, enabling the regio- and diastereoselective unsymmetrical diamination of arenes and alkenes.

Iridium catalysis can be used to achieve the challenging Z-retentive asymmetric allylic substitution reaction by trapping thermodynamically less stable anti-π-allyliridium intermediates. Now the isolation and characterization of these complexes is reported, providing hitherto elusive detailed mechanistic insights into this reaction.

The mode of action of the biological Dnd antiphage defence system to cleave foreign DNA was not known. Now the activities of Dnd protein complexes are revealed, and a mechanism to discriminate between self-DNA and invading DNA is proposed.

Carbonyl catalysis is mainly limited to strongly activated primary amines. Now, a chiral bifunctional pyridoxal organocatalyst is developed that enables the activation of the inert α C(sp³)–H bond of NH₂-unprotected benzylamines affording chiral β-aminoalcohols with high diastereo- and enantioselectivities.

Copper is unique among CO₂ electrocatalysts owing to its ability to produce multicarbon products at high rates; however, achieving selectivity for specific products remains challenging. Here, Cu surfaces decorated with alkaline earth metal oxides are found to strongly favour alcohols over hydrocarbons.

The hydrogenation of CO₂ into more valuable hydrocarbons is potentially attractive in the context of greenhouse gas removal schemes, although the efficiency of such processes is still limited. Now, a GaZrO_x oxide catalyst working in combination with an H-SSZ-13 zeolite enables the highly efficient hydrogenation of CO₂ to propane with minimal by-product production.

Metal utilization is important for the overall efficiency of heterogeneous catalysts, but reducing the amount of precious active phases is challenging due to intrinsic properties such as structure sensitivity. Now Hensen and colleagues engineer the interfaces of supported cobalt catalysts to overcome such structure sensitivity limitations in CO₂ hydrogenation.

Carbon dioxide reforming can be used to valorize hydrocarbon-containing CO₂ streams without the use of external reductants, but existing methods remain inefficient. Here, an HZSM-5-encapsulated nickel catalyst is introduced that features a remarkable methane dry reforming activity combined with high methane utilization.

Material–microbe hybrids represent a promising strategy for harnessing biochemical reactivity using sunlight, yet little is known about the effect of the interaction on the organism. Here the interface of a CO₂- and N₂-fixing bacterium to CdTe alters its biochemical pathways, resulting in quantum efficiency close to the theoretical limit.

Artificial enzymes have shown promise for a variety of applications, although their performance is hampered by the limited tunability of current designs. This work introduces a class of artificial enzymes based on metal–organic framework monolayers that feature an amino acid-coordinated metal centre and photoactive cofactors and can be assembled into an efficient artificial photosynthesis system.

Hydroxide exchange membrane fuel cells operating in alkaline electrolyte are more cost-effective than their proton exchange membrane counterparts, but their performance is still considerably lower. Now, a Ni–Mo–Nb metallic glass is put forward as a hydrogen oxidation reaction catalyst with high activity and stability in alkaline electrolyte.

Chiral piperidines are of importance in drug synthesis, but effective and broadly applicable methods for their production remain scarce. Now, a reductive Rh-catalysed method is developed for the introduction of chiral primary amines into reduced pyridinium salts, affording optically active piperidines.

The multihole mechanism of the oxygen evolution reaction on semiconductor electrodes has been hard to elucidate due to a lack of atomic-scale structural characterization of the material interface. Using pulse voltammetry and simulations of α-Fe₂O₃ photoanodes, this study predicts the chemical origin of the third-order rate dependence on holes.

Platinum is the most active catalyst for the hydrogen evolution reaction, but the specific mechanism and the influence of the alkali metal cations remain elusive in alkaline media. Now, electrical transport spectroscopy, electrochemical impedance spectroscopy and ab initio molecular dynamics simulations are combined to elucidate the role of alkali metal cations for this reaction in alkaline electrolyte.