Articles

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.

Conjugate cyanation of linear α,β-unsaturated aldehydes has remained an unsolved synthetic challenge. Now a method based on organocatalysis and photoredox catalysis is developed that facilitates this process asymmetrically, leading to an exclusive 1,4-chemoselectivity.

Direct CO₂ electroreduction on Cu-based catalysts has been used to produce C₂ products but yields of C₃ products have remained low. Here a CO₂ supersaturation strategy is used to promote electrodeposition of a highly alloyed CuAg electrode and its subsequent selectivity towards 2-propanol.

Electrosynthesis of higher carbon products (C₄₊) in a high selectivity has not been achieved by the direct reduction of CO₂ or CO. Here, the authors use a cascade electrocatalysis–thermocatalysis approach to produce butane from CO with an overall selectivity of 43%.

The dynamic transformation of Cu ions during the selective catalytic reduction of NO_x on Cu zeolites is well documented, although the function of the zeolite framework has not been fully understood. Here the authors unravel the role of anionic Al sites in the zeolite framework in regulating the mobility and reactivity of Cu cations during catalysis.

To overcome mass transport limitations in zeolite-catalysed reactions, scientists must often resort to hierarchical or nanosized zeolites; however, the synthesis of such materials remains challenging. Here the authors disclose a one-pot method for the preparation of Si-zoned MFI-type catalysts with improved diffusion properties for the methanol-to hydrocarbon reaction.

Although the Tetrahymena group I intron was the first RNA catalyst discovered, important mechanistic details remain ambiguous. Now six different conformational states of Tetrahymena group I intron self-splicing and an unexpected pseudoknotted structure are resolved by cryogenic electron microscopy.

Oxygen reduction to hydrogen peroxide is a promising alternative to replace the energy-intensive anthraquinone process in industry. Now, the hydrogen peroxide electrosynthesis performance of a carbon-supported cobalt phthalocyanine catalyst is tuned via the introduction of oxygen functional groups to the support, which optimize the electronic structure of cobalt active sites.

Polypyridine-ligated nickel complexes can mediate a variety of cross-coupling reactions. However, some mechanistic details remain poorly understood. Now, it is demonstrated that the nature of the anionic ligand strongly influences key electron-transfer events in these complexes during elementary reaction steps.

The catalytic cycle of formate dehydrogenase is generally assumed to involve an apoenzyme state according to the Theorell–Chance mechanism. Now, based on single-molecule experiments and multiscale simulations of formate dehydrogenase from Candida boidinii, an alternative mechanism that bypasses the apoenzyme state is proposed.

The practical optimizations of heterogeneous catalytic processes and reactor engineering are intertwined, but often what occurs inside the reactor remains elusive. Now, the molecular diffusion and carbon number of hydrocarbon products during Fischer–Tropsch synthesis on a Ru/TiO₂ catalyst are spatially resolved via magnetic resonance imaging in a pilot-scale fixed-bed reactor.

Large-scale deployment of electrocatalytic hydrogenations using water as a hydrogen source is hampered by poor solubility and difficult product separation. Here the authors propose a dual hydrogenation approach, with palladium membranes used as both anode and cathode, to produce hydrogen—enabled at the anode by the low-potential oxidation of formaldehyde—that permeates to adjacent chemical compartments, where the hydrogenation of organic substrates occur.

The cleavage of C–C bonds in hydrocarbons is traditionally entrusted to precious metal catalysts, whereas common non-reducible oxides are considered unreactive. Now, the authors report nanostructured silica-embedded zirconia nanoparticles that are competent for the hydrogenolysis of polyethylene with remarkable performance.

Hydrofunctionalization of α-olefins with mineral acids usually proceeds with Markovnikov selectivity. Now, a strategy based on synergistic phase transfer and photoredox catalysis is developed to facilitate anti-Markovnikov addition of aqueous hydrochloric and nitric acid to unactivated alkenes.

Lithium–sulfur batteries are promising energy storage devices where catalysis can play an important role, but developing design principles for optimal performance remains a challenge. Now, a series of p-block metal sulfide cathodes are evaluated, revealing a direct correlation between the p electron gain of sulfur in the sulfide material and the apparent activation energy for the sulfur reduction reaction.

Placing extra-framework aluminium species in the proximity of Brønsted acid sites is one of the most effective ways of tuning the energetics of zeolite-catalysed reactions. Here, using pentane cracking as an example, the authors show that grafting extra-framework silica species instead represents a valuable alternative way to modulate zeolite acitivty.

Albicidin is a peptide antibiotic that has shown great promise for inhibiting DNA topoisomerase of fluoroquinolone-resistant Gram-negative pathogens, but its mode of action is not fully clear. Now, cryoelectron microscopy structures of albicidin–gyrase complexes provide detailed insights into the mechanism of this natural product.

The design of complementary catalysts to target different C–H bonds in a specific molecule is challenging. Now, a pair of P450-based carbene transferase enzymes is engineered, which can selectively cyanomethylate either a C(sp³)–H or arene C(sp²)–H bond present in the same substrate.