Green chemistry

There is a real need to create materials capable of plastic recycling and upcycling. Here, the authors report a heterogeneous carbon nitride photocatalyst which efficiently converts polystyrene plastics into aromatic oxygenates, such as benzoic acid.

Lignin valorization becomes the spotlight on the full utilization of biomass. Here, the authors report a highly dispersed Ru catalyst for reductive catalytic fractionation of lignocellulose, which affords monophenols in theoretical maximum yields, along with high preservation of carbohydrate.

The separation of the rare-earth elements is a significant scientific challenge. Here, the authors report the selective precipitation of the light rare-earths as supramolecular capsules from acidic, industrially relevant, mixed-metal solutions.

Using CO2 as C1-feedstock for the chemical industry has attracted great attention. Here the authors develop a two-step cascade process to perform catalytic carbonylations of olefins, alkynes, and aryl halides using CO₂ and H₂.

Rare earth elements are essential to electrified infrastructure and clean energy production. Here, authors show reagent- and energy-efficient separation of lanthanides from secondary feedstock using dimethyl ether-driven fractional crystallization.

Deuterium-labelled compounds are useful for mechanistic studies and pharmaceutical science, but syntheses are not trivial. Here, the authors report deuteration of unactivated alkyl (pseudo)halides driven by electrochemical force, using deuterium oxide as the source of the isotope.

Decoupling the electronic and geometric effects has been a long cherished goal for heterogeneous catalysis due to their tangled relationship. Here the authors propose a novel orthogonal decomposition method to decouple the electronic and geometric effect for supported metal catalysts.

‘Polyethylene terephthalate is a widely used polymer with a concerning environmental impact, and alternatives are now highly sought. In this article, the authors present a biorefinery strategy for constructing polyester analogues of polyethylene terephthalate from woody biomass, which are promising candidates for the circular economy.

To solve the serious problem of white plastic pollution many degradation routes are being investigated. Here the authors show a H₂-free low-cost Cu/SiO₂ catalyzed process to quantitatively convert polyethylene terephthalate into p-xylene and ethylene glycol in one pot with methanol as both the solvent and hydrogen source at 210 °C.

An activated silver hollow fiber electrode enables enhanced triphasic interface reactions and oriented mass transfers synergistically, facilitating efficient CO₂ conversion (> 50%) to boost CO production with a current density of 1.26 A · cm⁻².

Peroxidase mimics are currently being investigated as catalysts for lignin depolymerisation. In this article, the authors investigate a class of self-assembled and highly stable peptoid/hemin nanomaterials as peroxidase mimics that are highly stable and tuneable for the depolymerisation of a biorefinery lignin.

CH4 oxidation to high value chemicals under mild conditions through photocatalysis confronts critical issues regarding both conversion and selectivity. Here, atomic Pd and oxygen vacancies were integrated on In2O3 nanorods, leading to visible-driven CH4 conversion with a remarkable yield of oxygenates and high selectivity of primary products.

Coordination environments around metal sites are important in electrocatalysis. Here, Ni metalloid oxidation produces oxyanion doped amorphous Ni-oxyhydroxides where substitution with phosphorus is found to boost methanol electrooxidation activity.

Single cluster catalysts are considered as versatile boosters in heterogeneous catalysis. Here the authors report subnanometric Cu clusters dispersed on Fe-doped MoO₂ support exhibits attractive performance in furfural valorization to C8-C15 aviation biofuels via a newly developed reaction route.

Biomass conversion holds promise as a more sustainable source of platform chemicals, but limitations in the ways in which lignin can be broken down is a current bottleneck. Here the authors report an electrocatalytic hydrogenolysis over skeletal Ni that cleaves diaryl ethers, chemically resistant moieties in both renewable carbon sources and persistent organic pollutants.

Liquid−liquid transitions (LLTs) have been reported for some molecular systems but are difficult to observe under high pressure conditions. Here the authors report and characterize a first-order LLT in a series of ionic liquids containing the trihexyl(tetradecyl)phosphonium cation and anions of different sizes and shapes, using calorimetric and dielectric measurements.

As of now, only rule-based systems support retrosynthetic planning using biocatalysis, while initial data-driven approaches are limited to forward predictions. Here, the authors extend the data-driven forward reaction as well as retrosynthetic pathway prediction models based on the Molecular Transformer architecture to biocatalysis.

Pd(II) catalyst turnover by reoxidation of a low valent Pd species is the key step for a Pd(II) catalyzed oxidation reaction. Here, the authors report a new strategy to address Pd reoxidation by fabricating spatially proximate photocatalyst and Pd(II) catalyst into metal-organic framework.

Current recycling methods suffer from harsh reaction conditions and long reaction times. Here the authors show a non-thermal plasma-assisted method for rapid hydrogenolysis of polystyrene at ambient temperature and atmospheric pressure, generating high yield (>40 wt%) of C1–C3 hydrocarbons.

Artificial photosynthesis offers an integrated means to convert light to fuel, but efficiencies are often low. Here, authors report a Z-scheme system utilizing Ir and FeCoO_x co-catalysts to enhance charge separation on BiVO₄ facets that achieves high quantum efficiencies for overall water splitting.

Proteins, other metabolites and many valuable synthetic products contain amide bonds and there is a need for more sustainable amide synthesis routes. Here the authors show an integrated next generation multi-catalytic system, merging nitrile hydratase enzymes with a Cu-catalysed N-arylation reaction in a single reaction vessel, for the construction of ubiquitous amide bonds.

Usually asymmetric hydrogenation of olefins is enantiodivergent and thus requires isomerically pure olefins, which is a considerable drawback. Here, the authors show a general iridium-catalyzed enantioconvergent hydrogenation of a broad range of functionalized trisubstituted olefins.

The recalcitrance of lignocellulosic biomass is the major limitation for the production of natural gas. Here the authors develop a catalytic-drive approach with Ni2Al3 alloy catalyst to enable nearly complete conversion of various agricultural and forestry residues into natural gas.

Grignard reagents have widespread utility in organic chemistry, but their preparation is limited by several drawbacks, such as the use of dry organic solvents and long reaction times. Here, the authors report a general mechanochemical synthesis of Grignard reagents in paste form in air, using a ball milling technique.

Time-resolved in situ (TRIS) X-ray powder diffraction promises great potential to study mechanochemical processes. Here, the authors develop a strategy to enhance the resolution of TRIS experiments to allow deeper interpretation of mechanochemical transformations; the method is applied to a variety of model systems including inorganic, metal-organic, and organic mechanosyntheses.

Deep eutectic solvents (DES) are intriguing green reaction media for biomass processing, however, undesired lignin condensation is a typical drawback. Here the authors develop a tunable ternary DES system that allows for stabilization of reactive intermediates for efficient lignocellulose fractionation.

Isobutene is a high value gaseous alkene that is widely used as fuel additive and a chemical building block. Here, the authors report an alternative pathway for isobutene bioproduction by directed evolution of prenylated FMN-dependent ferulic acid decarboxylase.

Plastic upcycling to value-added products is of great interests. Here the authors investigate a nickel-cobalt phosphide electrocatalyst for electroreforming of polyethylene terephthalate plastic toward valuable potassium diformate, terephthalic acid, and H₂ fuel.

Selective cleavage of C-C bonds is very important in organic chemistry, but remains challenging because of their inert chemical nature. Here, the authors report that Zn²⁺ coordinated with N species on N-doped carbon catalysts can catalyze the aerobic oxidative cleavage and esterification of C(CO)-C bonds with high efficiency and activity.

Single-atom Rh catalysts present superior activity in olefins hydroformylation, yet with limited success in regioselectivity control. Here the authors develop a Rh1 single-atom catalyst with nanodiamond as support, with which good to excellent regioselectivities to branched aldehydes in hydroformylation of terminal olefins are achieved.

Efficient production of benzene from lignin is attractive and of great importance, but has not been realized. Here, the authors develop a strategy to transform lignin into benzene over a RuW/zeolite catalyst in water, and the yield of benzene can be as high as 18.8% on lignin weight basis.

For printed electronics to realize its potential as a sustainable ubiquitous technology, eco-friendly solvents that deliver excellent ink performance must be found. Here, the authors report a free online tool that identifies functional green solvents for solution-processed printed electronics.

Compounds bearing a carbonyl group, such as aldehydes and ketones, are important industrial chemicals and widespread in pharmaceuticals and natural products. Here, the authors report a strategy for visible-light photoredox-catalyzed umpolung carboxylation of diverse carbonyl compounds with CO₂, to generate valuable α-hydroxycarboxylic acids.

The efficiency of chemical reactions in biological systems is often connected to the properties of confined water, but the developments and applications of artificial mimicking systems are impeded by the complexity of the biological systems. Here, the authors show how surface bound water in nanoporous cellulosic fibers can increase the reaction rate of surface acetylation reactions and enable regioselectivity of the reaction

The scale-up of the coupling of water electroreduction (HER) with organic electrooxidation remains challenging. Here the authors address this challenge by coupling HER with electrooxidation of raw biomass chitin, cogenerating acetate and green hydrogen safely at high current density.

To date we have a myriad of luminogenes at our deposal but many of them face problems like weakened emission in the aggregated state as well as poor sustainability. Here, the authors develop a class of rosin-derived luminogens with aggregation induced emission properties providing good biocompatibility and demonstrate their application in organelle imaging.

The solar-driven H₂ production from water by particulate photocatalysts is an effective approach to produce H₂ fuel. Here, the authors propose an integrated photothermal–photocatalytic biphase system, which lowers the reaction barrier and the delivery resistance of the H₂, boosting the catalytic H₂ evolution rate.

Selective hydrogenation of 5-(hydroxymethyl)furfural (HMF) to 5-Methylfurfural using H2 as reductant is very attractive, but remains challenging. Here, the authors report that isolated single atomic catalysts can catalyze the reaction efficiently with selectivity >99% at complete conversion of HMF.

Directional Solvent Extraction is an emerging non-membrane desalination technology for sea water desalination but is limited by throughput and energy efficiency. Here, the authors demonstrate that the production rate and energy efficiency can be increased by using ionic liquids as directional solvent.

Organocatalytic atom transfer radical polymerization (O-ATRP) is attractive due to its metal-free nature but catalysts are rarely applied at a low loading. Here the authors introduce a catalyst design logic based on heteroatom-doping of polycyclic arenes, which led to the discovery of oxygen-doped anthanthrene as an organic photoredox catalysts for O-ATRP.

C-lignin represents an ideal feedstock for producing catechol derivatives. Here, the authors engineered an atomically dispersed Ru catalyst, which can cleave C−O bonds efficiently and circumvent C=C bonds hydrogenation selectively, thus leading to propenylcatechol in high yields with high TONs.

Basic ionic liquids provide a buffering effect that enables the efficient synthesis of free formic acid from CO₂ hydrogenation. Here, a highly efficient catalytic system that transforms CO₂ to formic acid without the need of strong bases is demonstrated, avoiding the formation of formate salts.

Design and discovery of catalysts to make clean energy and mitigate the harmful effect of greenhouse gases remains a massive challenge. Here the authors report a combustion-synthesised iron-based catalyst of high activity and selectivity for directly converting CO₂ to aviation jet fuel.

The high bond energies of C–O bonds in biomass and its derivatives make their cleavage very challenging. Here, the authors report a photoredox-catalyzed C–O bond cleavage in diaryl ethers by acidolysis with an aryl carboxylic acid followed by hydrolysis in a one-pot manner.

Alcohols are more naturally abundant than carbonyl compounds, which in turn are well known for their reactivity in Grignard reactions. Here, the authors showcase a distinct Grignard-like reactivity by using alcohols as coupling partners with hydrazones and synthesize more complex alcohols under ruthenium catalysis.

The development of techniques capable of orchestrating the assembly of living cells into multicellular ensembles with synergistic and function is challenge. Here, the authors construct algal or algal/bacterial cells-based core shell-like structure based on aqueous two-phase system for synergic photosynthetic H₂ production.

Chiral 1,2-diamines are useful chemicals used as ligands in asymmetric catalysis. Here, the authors report a copper(I)-catalyzed asymmetric α-addition of ketimines derived from trifluoroacetophenone and 2- or 4-NO2-benzylamines to aldimines, affording a series of chiral anti-1,2-diamine derivatives.

Nitriles are key intermediates in production of pharmaceuticals, agrochemicals and organic materials. Here, the authors report a nickel-catalyzed reductive cyanation of organic chlorides with CO₂/NH₃ and urea as cyanation reagents to afford a broad range of organic nitriles.

Transparent wood composites are promising engineered materials for green energy-efficient building. Here, authors demonstrate novel aesthetic wood with integrated functions of optical transparency, UV-blocking, thermal insulation, and mechanical strength for this sustainable application.