Reviews & Analysis

Despite being used as a water-oxidation catalyst in alkaline electrolysis for over a century, the details of how Ni–Fe (oxy)hydroxide catalysts function remains unclear. Now, using a nanoparticle model system, the intrinsic activity and underlying catalytic mechanism is probed.

The mechanism of methanol coupling to methyl formate over single-crystal gold catalysts has been firmly established but barely reconciled with experiments performed under practical conditions. Now, a method to close this gap has been reported, which enables the prediction of the reaction´s selectivity for a broad range of experimental conditions.

The electroreduction of CO represents a promising approach toward artificial hydrocarbon synthesis, but its rate is limited by the sluggish transport of CO in aqueous electrolytes. Recent work shows how the issue can be circumvented by using gas diffusion electrodes.

Development of an earth-abundant and inexpensive copper-based catalyst is desirable for CO₂ hydrogenation. Now, the combined application of a stable copper hydride and a Lewis pair is shown to effect activation of CO₂ as well as heterolysis of H₂, achieving significant turnover numbers.

Heterogeneous photocatalysts are rarely employed in industry for the synthesis of commodity chemicals due to efficiency problems. Now, a photochromic Bi₂WO_6–x/amorphous-BiOCl composite is reported, which features a remarkable activity for the photocatalytic oxidation of toluene into benzaldehyde and benzoic acid.

Artificial metalloenzymes generally consist of a synthetic (organo)metallic catalyst incorporated into a protein. Asymmetric catalysis by such metalloenzymes could result by virtue of the chiral protein environment. Now, redox-sensitive anchoring enables reversible incorporation of an iridium catalyst for transfer hydrogenation.

Typically, catalysts are discovered through trial and error coupled with chemical intuition. Now, an automatic machine-learning framework has been developed that can guide itself to find intermetallic surfaces with desired catalytic properties.

Plasmonic catalysis has recently revolutionized the field of catalysis, promising to achieve improved control over catalytic reactions by targeting specific electronic excitations. In this Review, Linic and co-workers discuss the recent advances in the field, focusing on the underlying physical mechanisms and their application in catalysis, as well as limitations and future perspectives.

The general importance of electrostatic effects on catalysis is well appreciated, but their use in catalyst design is both promising and challenging. This Perspective discusses recent progress and future directions towards computational optimization of biological and chemical catalysis in terms of electric fields and their connections to experimental catalytic systems.

The chemical synthesis of natural products, such as sesquiterpenes, is a daunting task due to their complexity and precise functionalization, and multiple synthetic and purification steps that reduce overall yields are usually required. Now, a highly efficient alternative approach using supramolecular chemistry has been proposed by Tiefenbacher and co-workers.

Metalloprotein activity can be tuned by altering first- and second-sphere interactions with the metal ion or ions. Here, a non-canonical haem axial ligand is introduced into a myoglobin variant, modulating both. The resulting enhancement of cyclopropanation activity illustrates the utility of expanding the suite of available amino acids for biocatalyst engineering.

How the first metabolic network was organized to power a cell remains an enigma. Now, simple iron–sulfur peptides have been used to generate a pH-gradient across a protocell membrane by catalysing hydrogen peroxide reduction. This indicates that short peptides could have fulfilled the role of redox active metalloproteins in early life.

The histidine brace found in certain copper oxidases enables the oxidation of strong C–H bonds in organic substrates. This Perspective highlights and discusses the possible structural and electronic features of this motif and how these features underlie its role in challenging oxidative catalysis.

The identification of organic structure-directing agents capable of tailoring the physicochemical properties of microporous materials has remained a challenge. Now, a unique methodology to design organic mimics of reaction intermediates provides a route to optimize the selectivity of zeolite catalysts.

Control over the length and composition of polymers is key to controlling their properties. Now, a photoswitchable catalyst is shown to allow external control over reaction rates, chain lengths and even polymer composition in ring-opening polymerizations.

Pairing electrosynthetic anode and cathode processes (either convergent or divergent) is essential to maximize energy usage/sustainability and to minimize waste. New approaches to pairing in electrosynthesis are needed and the use of a palladium film membrane by Berlinguette and co-workers represents an effective paired reactor prototype that couples electrosynthesis with chemical catalysis.

The artificial synthesis of ammonia remains one of the most important catalytic processes worldwide, over 100 years after its development. In this Review, recent developments in enzymatic, homogeneous and heterogeneous catalysis towards the conversion of nitrogen to ammonia are discussed, with a particular focus on how mechanistic understanding informs catalyst design.

Although the replacement of palladium with iron in metal-catalysed cross-couplings continues apace, the Suzuki synthesis of biaryls — arguably the most widely used class of such C–C bond formations — has remained elusive. Now, by use of a π-coordinating directing group, another step has been taken toward iron-catalysed Suzuki reactions.

Iron–sulfur metalloproteins are widespread and efficient catalysts for multielectron reduction of small molecules. Now, research shows that simple Fe₄S₄ cofactors and related complexes can perform effective reductive chemistry producing small hydrocarbons from CO₂ and CO.

The carboxylation of aromatic compounds with CO₂ is an attractive reaction, albeit limited in scope. Now, bulky ligands in a Rh(II) catalysed C–H carboxylation of 2-arylphenols are shown to override the standard ortho/para Kolbe–Schmitt-type regioselectivity allowing instead carboxylation at 2’.