Volume 7 Issue 5, May 2024

The understanding of protein evolution is a central challenge in biology. Now, the evolution of a β-lactamase in vitro reveals that the total effect of mutations can change the rate-limiting step of the catalytic mechanism.

Platinum-free electrocatalysts for anion exchange membrane fuel cells and water electrolysers are required to improve the techno-economic viability of these electrochemical technologies for the sustainable production and use of hydrogen. Modifying the electronic structure of Li-intercalated layered Mn-oxides via Ru doping resulted in a catalyst displaying impressive performance towards both technologies.

The future of bioproduction lies in efficient C1 utilization. Methanol derived from CO₂ can be fed to engineered bacteria that convert it into platform chemicals currently produced from fossil fuels. Now, recent results confirm we are getting closer.

Material–microbe hybrids represent an interesting class of catalyst with potential for high energy efficiency and product selectivity. In this Perspective the authors discuss some of the difficulties in understanding these interdisciplinary systems and the attempts to unify the approaches taken by different research communities to further the field.

Atropisomerism is an expanding target of asymmetric catalysis. In this Review, recent advances in atroposelective synthesis under catalytic control are highlighted with a focus on general strategies that provide high versatility and modularity.

The reasons for epistasis, wherein mutations interact non-additively, are often not fully understood. Now it is found that shifting the rate-limiting step from substrate binding to the chemical reaction step during the directed evolution of β-lactamase correlates with epistasis.

Photoelectrocatalytic nitrate reduction offers an opportunity for a lower carbon route to ammonia production but has not been realized due to poor efficiency. Here an efficient modified lead halide perovskite photocathode is coupled to glycerol oxidation anode resulting in a bias-free photocurrent density greater than 20 mA cm⁻².

Photoelectrocatalysis offers the potential to reduce energy demand and provide different selectivity profiles compared with electrocatalytic analogues, but current systems have shown limited rates. Here, recent advances in light concentration and gas diffusion electrodes are integrated into a photoelectrochemical system for coupled glycerol oxidation and CO₂/H₂O reduction with photocurrent densities above 100 mA cm⁻².

Ethylene oxide is a key platform chemical that is produced industrially from the epoxidation of ethylene on silver catalysts, but the precise mechanism remains elusive. Now, in a joint computational–experimental effort, a phase of the silver catalyst grown on (100) facets that contains square-pyramidal subsurface oxygens and is stabilized by strongly adsorbed ethylene is identified as the active phase, and the mechanism is revealed.

The development of superior and cost-effective catalysts for the oxygen reduction and evolution reactions is pivotal for the future hydrogen economy. Now a series of Ru-modified Li₂MnO₃ catalysts have been designed to optimize the electronic structure and achieve a high performance in both oxygen reduction and evolution reactions, as demonstrated in practical anion exchange membrane fuel cell and water electrolyser tests.

Synthetic methylotrophic organisms provide potential for valorization of greenhouse gas-derived methanol. Here an Escherichia coli strain is generated that reaches a similar growth rate on methanol to many natural methylotrophs and is capable of producing chemicals from this carbon source.

The tunable design of molecular catalysts presents opportunities for the control of product selectivity in CO₂ reduction, yet to date, complexes capable of producing multicarbon products have been elusive. Here, a Br-bridged dinuclear Cu(I) complex that turns over C₃H₇OH is reported.

Direct stereoselective amination of tertiary C–H bonds without the assistance of directing groups is a challenging task in synthetic organic chemistry. Now a nitrene transferase is engineered to aminate tertiary C–H bonds with high enantioselectivity, providing direct access to valuable chiral α-tertiary primary amines.

Aminated heteroaromatics are usually synthesized from heteroaromatic substrates. Now, a general photochemical approach that exploits non-aromatic N-heterocyclic ketones as starting materials for the coupling with amines under desaturative catalysis is reported as an alternative.