Volume 1 Issue 7, July 2018

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.

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.

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.

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.

Electrolysis uses clean electricity to form chemical products but typical water electrolysis produces hydrogen which is hard to store oxygen which is a waste gas. Here, paired electrolysis is performed with an palladium membrane reactor to carry out two organic reactions simultaneously. The dense palladium membrane enables the two reactions to proceed in different solvents and the reaction rates and selectivities can be independently controlled.

The proper verification of the stability of metal oxide catalysts for water electrolysis in acid electrolyte remains unresolved. Here, the ‘stability number’ is introduced to evaluate the dissolution mechanisms of various iridium-based oxides and to facilitate benchmarking of catalysts independent of loading, surface area or involved active sites.

The properties of polymers depend on monomer composition and chain length, but regulating these structural features during polymer synthesis is a challenge. Now Hecht and co-workers report a photoswitchable catalyst system that can repeatedly be switched between ON and OFF states, allowing remote control of the polymerization process. Furthermore, copolymerization with control over monomer incorporation is demonstrated.

Organic synthesis relies on the ability to convert simple starting materials into compounds with greater molecular complexity. Here, Trost and co-workers use branched aldehydes as nucleophiles for asymmetric Mannich reactions, and the products of these reactions as electrophiles for the addition of a range of carbon nucleophiles. This provides a simple, stereodivergent route to 1,3-aminoalcohols.

Predicting metal–support combinations that can afford stable single-atom catalysts remains a complex problem. Now, a computational method is reported that can be used to screen interaction strengths between metals and supports and identify those pairs that generate strongly adsorbed single-atom catalysts.

Supported metal nanoparticles are indispensable catalysts in industry, yet they are often subjected to severe sintering. Now, a general method based on metal immobilization within zeolite is reported for the preparation of highly sinter-resistant catalysts for a broad range of industrially relevant processes.

Methanol-to-olefins (MTO) conversion over zeolites is a promising route for the production of light olefins. Now, Corma and co-workers show that using mimics of reaction intermediates as structure-directing agents allows the synthesis of highly selective zeolite MTO-catalysts.

The preparation of functionalized amino acids from inexpensive aldehydes is challenging. This work describes the biocatalytic synthesis of l-methionine by applying gaseous CO₂ pressure and a coupled amination step to drive the unfavoured equilibrium of a reverse carboxylation reaction.