Articles in 2022

Redox mediators catalyse the otherwise slow and energy-inefficient cycling of Li–S and Li–O₂ batteries. An investigation of the kinetics of mediated Li₂S and Li₂O₂ oxidations when the redox potentials of various mediators are tuned reveals threshold potentials for high reaction rates, which can be optimized in multiple ways.

The electrochemical production of ethylene oxide from CO₂ is an attractive yet challenging process. Now, a BaO_x/IrO₂ catalyst for ethylene oxidation is reported and applied in an O₂-redox-mediated paired system for complete CO₂ to ethylene oxide production.

The implementation of precious metal-free catalysts for the oxygen reduction reaction in fuel cells requires techniques that enable the study of catalyst degradation during operation. Now, an electrochemical method to quantify the density of electrochemically active sites in precious metal-free fuel cell catalysts under in situ conditions is presented.

The dynamic behaviour of low-nuclearity catalysts has major implications in their catalytic performance and is often overlooked. Here, it is shown how supported Rh catalysts undergo dynamic restructuring in response to gaseous products formed during steam reforming of methane.

Biological CO₂ fixation in cells is subject to natural limitations. Now a cell-free system with a cycle that is oxygen-insensitive and self-replenishing has been developed, allowing the conversion of CO₂ into several C₃ and C₄ products in vitro with a steady-state CO₂ fixation rate of 0.55 mM h⁻¹.

Metal–metal oxide inverse catalysts are an intriguing class of materials, although the understanding of their structure–activity properties remains elusive. Here, Vlachos and colleagues unravel the complex dynamic interplay between Brønsted acid and redox sites at the surface of a PtWO_x/C inverse catalyst, offering a strategy to tune its acid-catalysed dehydration reactivity.

Enantioselective C–C bond-forming reactions are underdeveloped in the biocatalysis toolbox. Now, engineering an efficient and promiscuous decarboxylative aldolase enzyme provides a solution to facilitate the convenient synthesis of non-standard γ-hydroxy amino acids from simple building blocks.

How terpene cyclases catalyse deprotonation–reprotonation sequences during their complex reactions has remained obscure. Now it is shown that selinadiene synthase uses the carbonyl group of a glycine residue and an active-site water molecule to mediate this process.

Polymer electrolyte membrane water electrolysis is more efficient than its alkaline counterpart, but its implementation, in part, hinges on developing Earth-abundant catalysts that are active and stable for the oxygen evolution reaction in acid. Now, it is shown that incorporating Mn into Co₃O₄ substantially extends the catalyst lifetime in acidic electrolyte while maintaining the activity.

The CO₂-mediated oxidative dehydrogenation of propane is an attractive reaction for propylene production, although the selection of competent catalysts available for this process is scant. Now, the authors report a ceria-supported Pt–Co–In ternary alloy that achieves this transformation with high efficiency.

The encapsulation of supported metal nanoparticles by a thin oxide support overlayer under reducing conditions is commonly referred to as a strong metal–support interaction. Now, by controlling the composition of the reducing agents at the catalyst activation stage, an adsorbate-induced strong metal–support interaction is reported for the commercial Cu/ZnO/Al₂O₃ catalyst during methanol steam reforming.

The conversion of methane to oxygenated molecules is a very challenging reaction that often requires the use of a coreductant or stoichiometric conditions. Here, the authors report the use of gold supported on ZSM-5 as a promising catalyst for this process in combination with oxygen in the absence of coreductants.