Reviews & Analysis

General catalytic methods for free radical-mediated asymmetric transformations have long eluded synthetic organic chemists. Now, NAD(P)H-dependent ketoreductases are repurposed and engineered as highly efficient photoenzymes to catalyse asymmetric radical C–C couplings.

Elucidating the reaction mechanism of a catalytic process is very challenging. Now, advanced solid-state nuclear magnetic resonance experiments demonstrate the importance of oxygenates to regulate the conversion of synthesis gas over an oxide–zeolite-based bifunctional catalyst material.

Rationalizing the difference in the catalytic properties within a group of materials is a challenging task. A method is now proposed that addresses this issue by predicting the activity and stability of platinum-based electrocatalysts from operando spectroscopic data.

The direct use of ammonia for asymmetric synthesis is highly sought after. Now, an efficient enantioselective carbene insertion into the N–H bond of ammonia has been developed, producing diverse valuable chiral α-amino acids.

Supported subnanometre catalysts are atom efficient and possess unique properties, but their structure–activity relations are not well understood. Now it is possible to reveal their structure sensitivity by combining multimodal experiments and computations.

The oxygen reduction reaction (ORR) plays a central role in electrochemistry for applications such as energy conversion and storage. This Review focuses on the fundamentals, technology and perspectives of ORR as an abiotic or biotic process at near neutral pH.

Molecular catalysts anchored on electrode surfaces are commonly assumed to behave similarly to their homogeneous counterparts. Under some conditions, however, they can behave like metallic electrodes. Now, the underlying phenomena behind this fresh paradigm in heterogeneous electrocatalysis are uncovered.

Bioelectrochemical CO₂ fixation often suffers from a mismatch between the electrochemical and biological components. Now, a spatial decoupling strategy, where CO₂ electrolysis produces electrolyte-free acetic acid as the feed for engineered yeast fermentation, enables highly productive synthesis of glucose or fatty acids.

Nitrogenase reduces dinitrogen at one of its iron–sulfur cores to produce ammonia by a convoluted mechanism. Now, research highlights the importance of sulfur mobility on one of nitrogenase’s metallocofactors for nitrogen fixation.

Combining computational and experimental methods is a powerful approach, but these are not always directly comparable. This Perspective discusses the relationship between experimental measurements and theoretical calculations in electrocatalysis and aims to enhance the connections between the two.

Reliable testing of fuel cell and electrolyser catalysts is crucial for comparison between studies. This Perspective discusses the differences between rotating disk electrode (RDE) and membrane electrode assembly (MEA) testing of electrocatalysts, and identifies where RDE can be useful and when MEA is more appropriate to study activity and stability under realistic conditions.

Selective electroreduction of CO₂-derived CO presents an opportunity to produce sustainable fuels and chemicals; however, its performance has been below practical levels. Now, an ordered Cu–Pd bimetallic catalyst has been developed for selective electroreduction of CO to acetate at an industrially relevant activity.

Low-temperature CO₂ electrolysis is increasingly attractive for the production of sustainable electrofuels and electrochemicals as intensified research keeps pushing performance higher. Recent efforts on system engineering now offer solutions to downstream purification challenges, taking this technology one step closer to maturity.

Studying the kinetics of high-energy and high-power batteries is a formidable challenge. Now, it has been shown that redox-mediated (RM) catalysis in Li–O₂ and Li–S batteries can be controlled by tuning parameters such as Li-ion concentration or electrolyte solvent, revealing threshold potentials in which rate constants increase several-fold.

Most applications of machine learning in catalysis use black-box models to predict physical properties, but extracting meaningful physical insights from them is challenging. This Perspective discusses machine learning approaches for heterogeneous catalysis and classifies them in terms of their interpretability.

Solid catalysts often exhibit a dynamic behaviour when exposed to reactive environments. Now, a study showcases how such behaviour can be exploited to maximize activity.

For microbial industrial lignin conversion, a key challenge is to overcome rate-limiting steps in the upper pathways of aromatic catabolism. This Review discusses the critical enzymatic reactions of aromatic O-demethylation, decarboxylation and hydroxylation for lignin valorization via biological funnelling.

Phosphorus compounds with unique chirality due to the presence of a P-stereocentre are obtained through stereoselective catalytic cross-coupling of phosphoramidites and aryl halides. Axial-to-central transfer of chirality is shown to provide ready access to various classes of P-chirogenic compounds that are key to catalysis and drug development.

A new class of catalysts based on ternary ruthenium complex hydrides are developed for low-temperature ammonia synthesis. They support a non-dissociative reaction path for dinitrogen reduction, in which lithium or barium cations stabilize the N_xH_y intermediates and the electron- and H-rich [RuH₆]^4– anionic centres facilitate an energetically balanced multi-step reaction for ammonia synthesis.

Liquid fuels produced by electrocatalytic CO₂ reduction are costly to separate from liquid electrolytes in a conventional cell. This Perspective identifies the need for novel cell designs that can directly produce high-concentration and high-purity products and discusses the progress towards this goal using porous solid electrolytes.