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Plastic wastes represent a largely untapped resource for manufacturing chemicals and fuels, particularly considering their environmental and biological threats. Here we report electrocatalytic upcycling of polyethylene terephthalate (PET) plastic to valuable commodity chemicals (potassium diformate and terephthalic acid) and H 2 fuel. Preliminary techno-economic analysis suggests the profitability of this process when the ethylene glycol (EG) component of PET is selectively electrooxidized to formate (>80% selectivity) at high current density (>100 mA cm −2 ). A nickel-modified cobalt phosphide (CoNi 0.25 P) electrocatalyst is developed to achieve a current density of 500 mA cm −2 at 1.8 V in a membrane-electrode assembly reactor with >80% of Faradaic efficiency and selectivity to formate. Detailed characterizations reveal the in-situ evolution of CoNi 0.25 P catalyst into a low-crystalline metal oxy(hydroxide) as an active state during EG oxidation, which might be responsible for its advantageous performances. This work demonstrates a sustainable way to implement waste PET upcycling to value-added products. 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 H 2 fuel.

Electrochemical alcohols oxidation offers a promising approach to produce valuable chemicals and facilitate coupled H 2 production. However, the corresponding current density is very low at moderate cell potential that substantially limits the overall productivity. Here we report the electrooxidation of benzyl alcohol coupled with H 2 production at high current density (540 mA cm −2 at 1.5 V vs . RHE) over a cooperative catalyst of Au nanoparticles supported on cobalt oxyhydroxide nanosheets (Au/CoOOH). The absolute current can further reach 4.8 A at 2.0 V in a more realistic two-electrode membrane-free flow electrolyzer. Experimental combined with theoretical results indicate that the benzyl alcohol can be enriched at Au/CoOOH interface and oxidized by the electrophilic oxygen species (OH*) generated on CoOOH, leading to higher activity than pure Au. Based on the finding that the catalyst can be reversibly oxidized/reduced at anodic potential/open circuit, we design an intermittent potential (IP) strategy for long-term alcohol electrooxidation that achieves high current density (>250 mA cm −2 ) over 24 h with promoted productivity and decreased energy consumption. Electrochemical alcohol oxidation offers a promising approach to produce valuable chemicals that can be paired with fuel-producing reactions. Here, authors utilize gold and cobalt oxyhydroxide nanomaterials to obtain industrially-relevant electrolyzer current densities for benzyl alcohol oxidation.

Photoelectrochemical cells are emerging as powerful tools for organic synthesis. However, they have rarely been explored for C–H halogenation to produce organic halides of industrial and medicinal importance. Here we report a photoelectrocatalytic strategy for C–H halogenation using an oxygen-vacancy-rich TiO 2 photoanode with NaX (X=Cl − , Br − , I − ). Under illumination, the photogenerated holes in TiO 2 oxidize the halide ions to corresponding radicals or X 2 , which then react with the substrates to yield organic halides. The PEC C–H halogenation strategy exhibits broad substrate scope, including arenes, heteroarenes, nonpolar cycloalkanes, and aliphatic hydrocarbons. Experimental and theoretical data reveal that the oxygen vacancy on TiO 2 facilitates the photo-induced carriers separation efficiency and more importantly, promotes halide ions adsorption with intermediary strength and hence increases the activity. Moreover, we designed a self-powered PEC system and directly utilised seawater as both the electrolyte and chloride ions source, attaining chlorocyclohexane productivity of 412 µmol h −1 coupled with H 2 productivity of 9.2 mL h −1 , thus achieving a promising way to use solar for upcycling halogen in ocean resource into valuable organic halides. Photoelectrochemical cells are promising tools for C–H functionalisation coupled with H2 production. In this work, Duan et. al., reported the photoelectrocatalytic C–H halogenation to produce organic halides of industrial and medicinal importance with promoted H 2 production.

Electrooxidation of biomass platforms provides a sustainable route to produce valuable oxygenates, but the practical implementation is hampered by the severe carbon loss stemming from inherent instability of substrates and/or intermediates in alkaline electrolyte, especially under high concentration. Herein, based on the understanding of non-Faradaic degradation, we develop a single-pass continuous flow reactor (SPCFR) system with high ratio of electrode-area/electrolyte-volume, short duration time of substrates in the reactor, and separate feeding of substrate and alkaline solution, thus largely suppressing non-Faradaic degradation. By constructing a nine-stacked-modules SPCFR system, we achieve electrooxidation of glucose-to-formate and 5-hydroxymethylfurfural (HMF)-to-2,5-furandicarboxylic acid (FDCA) with high single-pass conversion efficiency (SPCE; 81.8% and 95.8%, respectively) and high selectivity (formate: 76.5%, FDCA: 96.9%) at high concentrations (formate: 562.8 mM, FDCA: 556.9 mM). Furthermore, we demonstrate continuous and kilogram-scale electrosynthesis of potassium diformate (0.7 kg) from wood and soybean oil, and FDCA (1.17 kg) from HMF. This work highlights the importance of understanding and suppressing non-Faradaic degradation, providing opportunities for scalable biomass upgrading using electrochemical technology. Electrooxidation of biomass provides a sustainable route to produce valuable chemicals, but suffers from non-Faradaic degradation in alkaline electrolysis at high reactant concentration. Here, the authors develop a single-pass continuous flow reactor to tackle this challenge, achieving kilogram-scale and continuous electrooxidation of glucose to formate and 5-hydroxymethylfurfural to 2,5-furandicarboxylic acid with high selectivity and high concentration.

Hydrogen production via electrochemical water splitting is one of the most green and promising ways to produce clean energy and address resource crisis, but still suffers from low efficiency and high cost mainly due to the sluggish oxygen evolution reaction (OER) process. Alternatively, electrochemical hydrogen‐evolution coupled with alternative oxidation (EHCO) has been proposed as a considerable strategy to improve hydrogen production efficiency combined with the production of high value‐added chemicals. Although with these merits, high‐efficient electrocatalysts are always needed in practical operation. Typically, layered double hydroxides (LDHs) have been developed as a large class of advanced electrocatalysts toward both OER and EHCO with high efficiency and stability. In this review, we have summarized the latest progress of hydrogen production from the perspectives of designing efficient LDHs‐based electrocatalysts for OER and EHCO. Particularly, the influence of structure design and component regulation on the efficiency of their electrocatalytic process have been discussed in detail. Finally, we look forward to the challenges in the field of hydrogen production via electrochemical water splitting coupled with organic oxidation, such as the mechanism, selected oxidation as well as system design, hoping to provide certain inspiration for the development of low‐cost hydrogen production technology. In this review, we have summarized the latest research progress of hydrogen production from the perspectives of designing efficient LDHs‐based electrocatalysts for OER and EHCO. Meanwhile, the challenges in the field of hydrogen production via electrochemical water splitting coupled with organic oxidation have been raised.

Adipic acid is an important building block of polymers, and is commercially produced by thermo-catalytic oxidation of ketone-alcohol oil (a mixture of cyclohexanol and cyclohexanone). However, this process heavily relies on the use of corrosive nitric acid while releases nitrous oxide as a potent greenhouse gas. Herein, we report an electrocatalytic strategy for the oxidation of cyclohexanone to adipic acid coupled with H 2 production over a nickel hydroxide (Ni(OH) 2 ) catalyst modified with sodium dodecyl sulfonate (SDS). The intercalated SDS facilitates the enrichment of immiscible cyclohexanone in aqueous medium, thus achieving 3.6-fold greater productivity of adipic acid and higher faradaic efficiency (FE) compared with pure Ni(OH) 2 (93% versus 56%). This strategy is demonstrated effective for a variety of immiscible aldehydes and ketones in aqueous solution. Furthermore, we design a realistic two-electrode flow electrolyzer for electrooxidation of cyclohexanone coupling with H 2 production, attaining adipic acid productivity of 4.7 mmol coupled with H 2 productivity of 8.0 L at 0.8 A (corresponding to 30 mA cm −2 ) in 24 h. Adipic acid is an important building block of polymers, although its production relies on harmful reagents. Here, authors examined surfactant-modified nickel hydroxide for adipic acid electrosynthesis coupled with hydrogen gas evolution.

Enzymes are characteristic of catalytic efficiency and specificity by maneuvering multiple components in concert at a confined nanoscale space. However, achieving such a configuration in artificial catalysts remains challenging. Herein, we report a microenvironment regulation strategy by modifying carbon paper with hexadecyltrimethylammonium cations, delivering electrochemical carbon–carbon coupling of benzaldehyde with enhanced activity and racemate stereoselectivity. The modified electrode–electrolyte interface creates an optimal microenvironment for electrocatalysis—it engenders dipolar interaction with the reaction intermediate, giving a 2.2-fold higher reaction rate (from 0.13 to 0.28 mmol h −1 cm −2 ); Moreover, it repels interfacial water and modulates the conformational specificity of reaction intermediate by facilitating intermolecular hydrogen bonding, affording 2.5-fold higher diastereomeric ratio of racemate to mesomer (from 0.73 to 1.82). We expect that the microenvironment regulation strategy will lead to the advanced design of electrode–electrolyte interface for enhanced activity and (stereo)selectivity that mimics enzymes. Positioning multiple components in a confined space increases the efficiency of many transformations catalyzed by enzymes but achieving such configuration in artificial catalysts remains challenging. Here, the authors demonstrate that modifying carbon paper with hexadecyltrimethylammonium cations can position reactants for efficient electrochemical carbon–carbon coupling of benzaldehyde with enhanced racemate stereoselectivity.

Steering on the intrinsic active site of an electrode material is essential for efficient electrochemical biomass upgrading to valuable chemicals with high selectivity. Herein, we show that an in-situ surface reconstruction of a two-dimensional layered CdPS 3 nanosheet electrocatalyst, triggered by electrolyte, facilitates efficient 5-hydroxymethylfurfural (HMF) hydrogenation to 2,5-bis(hydroxymethyl)furan (BHMF) under ambient condition. The in-situ Raman spectroscopy and comprehensive post-mortem catalyst characterizations evidence the construction of a surface-bounded CdS layer on CdPS 3 to form CdPS 3 /CdS heterostructure. This electrocatalyst demonstrates promising catalytic activity, achieving a Faradaic efficiency for BHMF reaching 91.3 ± 2.3 % and a yield of 4.96 ± 0.16 mg/h at − 0.7 V versus reversible hydrogen electrode. Density functional theory calculations reveal that the in-situ generated CdPS 3 /CdS interface plays a pivotal role in optimizing the adsorption of HMF* and H* intermediate, thus facilitating the HMF hydrogenation process. Furthermore, the reconstructed CdPS 3 /CdS heterostructure cathode, when coupled with MnCo 2 O 4.5 anode, enables simultaneous BHMF and formate synthesis from HMF and glycerol substrates with high efficiency. Targeting the electrosynthesis of valuable chemicals from biomass-based feedstocks requires understanding the phenomena at the interface and electrode surface. Here, the authors demonstrate electrolyte-driven surface reconstruction on layered CdPS3 nanosheets for the efficient hydrogenation of 5-hydroxymethylfurfural.

Despite significant advances in the fabrication and applications of graphene-like materials, it remains a challenge to prepare single-layered metallic materials, which have great potential applications in physics, chemistry and material science. Here we report the fabrication of poly(vinylpyrrolidone)-supported single-layered rhodium nanosheets using a facile solvothermal method. Atomic force microscope shows that the thickness of a rhodium nanosheet is <4 Å. Electron diffraction and X-ray absorption spectroscopy measurements suggest that the rhodium nanosheets are composed of planar single-atom-layered sheets of rhodium. Density functional theory studies reveal that the single-layered Rh nanosheet involves a δ-bonding framework, which stabilizes the single-layered structure together with the poly(vinylpyrrolidone) ligands. The poly(vinylpyrrolidone)-supported single-layered rhodium nanosheet represents a class of metallic two-dimensional structures that might inspire further fundamental advances in physics, chemistry and material science. Single-layered materials such as graphene are well known, but metallic elements tend to favour three-dimensional clusters. Here the authors report the synthesis of rhodium nanosheets—a supported, single-layered metallic material with rare δ-bonding.

Electrosynthesis of adipic acid (a precursor for nylon-66) from KA oil (a mixture of cyclohexanone and cyclohexanol) represents a sustainable strategy to replace conventional method that requires harsh conditions. However, its industrial possibility is greatly restricted by the low current density and competitive oxygen evolution reaction. Herein, we modify nickel layered double hydroxide with vanadium to promote current density and maintain high faradaic efficiency (>80%) within a wide potential window (1.5 ~ 1.9 V vs. reversible hydrogen electrode). Experimental and theoretical studies reveal two key roles of V modification, including accelerating catalyst reconstruction and strengthening cyclohexanone adsorption. As a proof-of-the-concept, we construct a membrane electrode assembly, producing adipic acid with high faradaic efficiency (82%) and productivity (1536 μmol cm −2 h −1 ) at industrially relevant current density (300 mA cm −2 ), while achieving >50 hours stability. This work demonstrates an efficient catalyst for adipic acid electrosynthesis with high productivity that shows industrial potential. Here, authors use a membrane electrode assembly is conducted to produce adipic acid with high faradaic efficiency and productivity at an industrially relevant current density, while achieving >50 hours stability.