Research articles

Kinetic measurements often involve complex processes, and deconvoluting them to derive active-site chemistry becomes challenging. Now experimental kinetic measurements, density functional theory calculations and microkinetic modelling are combined to provide detailed mechanistic understanding of elementary reactions for ethylene hydrogenation on Pd–Zn γ-brass with isolated active sites.

Ethylene glycol is commercially produced from ethylene under energy-intensive thermocatalytic conditions. Now a cascade electrochemical heterogeneous system can produce ethylene glycol from ethylene or from CO₂ under ambient conditions using electrocatalytically generated H₂O₂ and an integrated catalyst/solid-acid composite.

Hydrogen carriers play an important role in the hydrogen economy. Now, methyl formate is proposed as a suitable chemical hydrogen source for a carbon-neutral hydrogen energy cycle, and faster catalytic hydrogen production rates are achieved compared with those from the widely investigated formic acid and methanol.

Organic semiconductors have potential for application as photocatalysts, but their efficiency is limited by recombination of charge carriers before they can reach the surface. Here hydrogen-bonded organic frameworks with designed micropores decrease the exciton transfer path to improve charge utilization in photocatalytic H₂ evolution.

CO₂ methanation offers a route to synthetic methane production but typically requires high temperatures to achieve sufficient rates. This study presents light-driven CO₂ methanation on an Au/Ce_0.95Ru_0.05O₂ solid-solution catalyst with high CH₄ production rate and selectivity benefiting from synergistic photochemical and photothermal effects.

While hydrosulfenation via addition of sulfenic acid to alkynes was reported decades ago, an asymmetric version of this reaction remained elusive. Now, Ni-catalysed hydrosulfenation of alkynes with in situ-generated sulfenic acids enables the synthesis of chiral alkenyl sulfoxides.

Molecular insights into the mechanism of amide bond formation in the biosynthesis of lincosamide antibiotics remain scarce. Now, the crystal structure of the condensation enzyme CcbD that catalyses this reaction is solved, its substrate scope investigated and a catalytic mechanism proposed.

Supported subnanometric clusters are a much sought-after class of catalyst, but governing the anchoring onto the support and the resulting properties of the clusters remains a challenge. Now the authors show how UTL-type germanosilicate can stabilize ultra-fine Pt clusters, resulting in a superior catalyst for propane dehydrogenation.

Shuttle catalysis is a promising approach to improve traditional hydrofunctionalization reactions, although thermodynamic constraints limit its application. Here the authors show how the properties of zeolites can drive the shuttling equilibrium of such catalytic processes, widening the applicability of reactions such as transfer hydrocyanation and transfer hydroformylation.

Pyridoxal 5′-phosphate (PLP)-dependent enzymes that catalyse Mannich reactions were unknown. Now, it is reported that the PLP-dependent enzyme LolT catalyses a 5-endo-trig Mannich cyclization reaction during the pyrrolizidine core scaffold formation in loline biosynthesis, and its crystal structure is solved.

Design of artificial photosynthetic systems that mimic the complex supramolecular structures in natural systems remains a grand challenge. Here self-assembled nanomicelles containing Zn porphyrins and Co porphyrins as photosensitizer and catalyst achieve selective photocatalytic CO₂-to-CH₄ conversion in water.

Saccharomyces cerevisiae can be engineered to slowly use methanol; however, a co-carbon source is usually required to support its growth. Now, a Saccharomyces cerevisiae strain that can use methanol as the sole carbon source for growth, and produce value-added bioproducts, is developed.

Electrocatalytic processes involving gas molecules are generally limited by low solubility in aqueous solutions. Here water endowed with permanent microporosity by silicalite-1 nanocrystals is used to concentrate O₂, allowing the measurement of the intrinsic activity of a Pt/C catalyst in the oxygen reduction reaction.

Nitrogenases are of high interest due to their ability to form NH₄⁺ by reduction of atmospheric dinitrogen. However, the detailed architecture of the Fe-only isoform remained unknown. Now, a high-resolution crystal structure of Fe-nitrogenase is solved, deepening the understanding of nitrogenase catalysis.

Charge transfer and chemical kinetics both contribute to the overall overpotential that is observed in a typical electrocatalytic experiment, but it remains difficult to resolve the individual contributions. Here a Pd membrane double cell is used to separate the charge transfer and chemical steps in the hydrogen evolution reaction to evaluate how experimental conditions affect the individual steps.

Electrocatalytic nitrate reduction represents an opportunity to generate ammonia under ambient conditions, yet the efficiency has been limited by the large overpotential required. Here, a Ru–Co alloy demonstrates a three-step relay mechanism involving a spontaneous redox step that reduces the overpotential for the process.

The Lebedev process is an established approach to convert ethanol into butadiene catalysed by silica–magnesia prepared by the so-called wet-kneading method. However, the role and impact of this wet-kneading approach have not been fully uncovered. Here the authors reveal important aspects of this process and elucidate the role of the different active sites it generates within silica–magnesia.

Although homogeneous hydride transfer reactivity is well understood, the heterogeneous counterpart at metal surfaces remains rather unexplored. This work introduces the electrocatalytic hydrogen reduction reaction, which in net reduces H₂ to reactive hydrides via the intermediacy of surface M−H species. The study reveals that hydride transfer from surface M−H species can be driven by electrical polarization.

The full potential of the well-known platinum oxygen reduction catalyst has not been realized in membrane electrode assembly for fuel cells due to the detrimental impacts of the required ionomer layer. Here the authors show how cyclohexanol can block the interaction between Pt and sulfonate groups of Nafion with benefits for reaction kinetics and mass transport.

The catalyst layer in proton-exchange membrane fuel cells involves the complex and crucial interplay between an ionomer network and metallic nanoparticles supported on carbons, but current methods are unable to describe it with high resolution. Now electron tomography at cryogenic temperatures and deep learning algorithms are used to provide quantitative three-dimensional imaging at nanometre resolution of a fuel cell catalyst layer structure.