Articles in 2021

Understanding the mechanism for the catalytic conversion of NO_x is crucial to develop superior greenhouse gas abatement schemes, although it remains challenging. Here, the authors reveal important aspects of the redox properties of NO_x on a La_1–xSr_xCoO₃ perovskite by a combination of density functional theory calculations and ambient-pressure X-ray photoelectron spectroscopy.

Single-atom catalysts containing Fe–N₄ active sites have been developed as effective noble-metal-free catalysts for the oxygen reduction reaction. Here the authors untangle the effects of active site density and cooperativity between neighbouring single-atom sites at well-defined distances.

The coupling of substituted thiophenes is central to the synthesis of conducting polymers but relies on costly Pd-catalysed cross-couplings. Here, Earth-abundant iron and aluminium are shown to catalyse a regioselective thienyl C–H/C–H dimerization, enabling the synthesis of an array of π-conjugated polythiophenes.

Molecular imprinting can facilitate size- and shape-selective reactions beyond traditional approaches based on porous materials, but is still not fully established for heterogeneous catalysts. Here a molecular imprinting approach is introduced to generate a supported palladium catalyst for the selective hydrogenation of benzene from mixtures of aromatic molecules.

The S_N2 reaction is essential in organic chemistry, but its substrate scope is limited. Now, a strategy based on halogen-atom transfer using α-aminoalkyl radicals and copper catalysis enables coupling of secondary alkyl iodides with N-nucleophiles with S_N2-like programmability.

Deuterated compounds are of high interest to the pharmaceutical industry; however, modular creation of differently deuterated methyl and methylene groups in organic skeletons is challenging. Now, this has been achieved by introducing the concept of transition-metal-mediated 1,4-H or D delivery.

Despite its biocidal properties, the use of hydrogen peroxide is still limited in the context of water disinfection. Here an approach is disclosed based on the generation of H₂O₂ in situ by means of an AuPd catalyst, which can compete with chlorination methods by generating a highly reactive radical flux.

The selective semihydrogenation of acetylene in ethylene-rich gas streams is an important process in the manufacture of polyethylene, which is traditionally performed thermocatalytically. Now, a room-temperature electrochemical acetylene reduction system with excellent performance is presented.

Acetylene semihydrogenation is important for polyethylene production, but the current thermocatalytic process is not free of shortcomings, such as the use of excessive hydrogen. Now, an electrocatalytic strategy is reported for selectively reducing acetylene to ethylene under ambient conditions

DYW domains catalyse cytidine deamination in plant RNA editing, but information on their structure and mode of action were lacking. Now, crystal structures of the DYW domain are reported and a gating domain, key catalytic residues and an unusual protein regulation mechanism are revealed.

Supported single-atom catalysts often feature a distinct reactivity when compared to traditional heterogeneous or homogeneous systems. Here the authors introduce a supported iridium single-atom catalyst for carbenoid O–H insertion characterized by a remarkable selectivity for aliphatic versus aromatic alcohols, unlike its homogeneous counterpart.

Structurally complex polyamines and polyamine analogues show potential as therapeutics and agrochemicals, but their production remains hampered. Here a polyamine yeast cell factory is developed that enables the gram-per-litre-scale titres of spermidine and the complete biosynthesis of a broad set of these compounds.

Copper-zinc-alumina is used in industry to catalyse the synthesis of methanol from CO₂, but many aspects of its high performance remain elusive. Now, by using in situ and operando techniques over four orders of magnitude in pressure, the authors show how the catalyst structure and kinetics change with the applied conditions.

Single-atom catalysts have become a frontier of heterogeneous catalysis, but to achieve a high stability under turnover is often a challenge. Now, a Pd/CeO₂ single-atom catalyst prepared using flame spray pyrolysis is able to stabilize the isolated Pd species during CO oxidation due to a high mobility of surface lattice oxygen.

The structural stability of electrocatalysts with complex nanoscale morphology, a requirement for their industrial implementation, often remains elusive. Now, a combination of electrical and electrochemical effects is shown to drive specific structural transformations of the catalyst during electrolysis.

Stereodivergent catalysis was previously limited to two possible states per stereogenic element. Now, it is demonstrated that stereoselective catalysis is capable of governing higher-order stereogenicity and the catalyst-controlled synthesis of four of the six possible stereoisomers arising from a single stereogenic unit is showcased.

Transition metal oxides constitute a promising class of catalysts for the oxygen reduction reaction, but they are found generally to be less active than Pt. Now, computational analyses and high-throughput experiments are used to understand the reasons behind the lower activity, and strategies to improve them are proposed.

Hydrogen peroxide is an interesting target for artificial photosynthesis, although its actual production via the two-electron oxygen reduction reaction remains limited. Now, a carbon nitride-supported antimony single atom photocatalyst has been developed with a superior performance for this process.

In the face of global plastic pollution, enzymatic degradation of poly(ethylene terephthalate) (PET) has attracted much attention. Now, structural and biochemical studies reveal a minimal mutational strategy to increase the activity of PET-degrading enzymes, with potential evolutionary implications.

Conductive polymers are attractive materials for the construction of photoelectrodes in the context of artificial photosynthesis, although their performance is still limited. Now, an organic semiconductor photoanode for water oxidation is presented, which provides high photocurrent density for over 30 minutes.