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The recycling of plastic waste is one of the most urgent issues in the 21st century owing to its detrimental impact on the environment and human health. However, it is greatly challenging to develop more efficient, low-cost and general methods capable of selectively converting plastic waste into added-value and separable chemicals while restricting their distribution. Here, we report a general electrocatalytic strategy for the selective upcycling of various polyester plastics into added-value chemicals by a CuCo2O4/Ni foam catalyst under mild conditions. In particular, polyethylene terephthalate (PET) was upcycled into terephthalate and formate with high efficiency and selectivity (>86%) even at a high current density of 100 mA cm−2. The electrocatalytic reaction mechanism was thoroughly elucidated by electrochemical in situ FTIR, NMR and DFT calculations. This work not only develops a superior electrocatalyst for upcycling various polyester plastics, but also provides guidance for the design of new and efficient electrocatalysts. [ABSTRACT FROM AUTHOR]

We report the synthesis of two‐dimensional metal–organic frameworks (MOFs) on nickel foam (NF) by assembling nickel chloride hexahydrate and 1,1′‐ferrocenedicarboxylic acid (NiFc‐MOF/NF). The NiFc‐MOF/NF exhibits superior oxygen evolution reaction (OER) performance with an overpotential of 195 mV and 241 mV at 10 and 100 mA cm−2, respectively under alkaline conditions. Electrochemical results demonstrate that the superb OER performance originates from the ferrocene units that serve as efficient electron transfer intermediates. Density functional theory calculations reveal that the ferrocene units within the MOF crystalline structure enhance the overall electron transfer capacity, thereby leading to a theoretical overpotential of 0.52 eV, which is lower than that (0.81 eV) of the state‐of‐the‐art NiFe double hydroxides. [ABSTRACT FROM AUTHOR]

Abstract: An electrochemical approach is developed that allows for the control of both proton and electron transfer rates in the O2 reduction reaction (ORR). A dinuclear Cu ORR catalyst was prepared that can be covalently attached to thiol‐based self‐assembled monolayers (SAMs) on Au electrodes using azide–alkyne click chemistry. Using this architecture, the electron transfer rate to the catalyst is modulated by changing the length of the SAM, and the proton transfer rate to the catalyst is controlled with an appended lipid membrane modified with proton carriers. By tuning the relative rates of proton and electron transfer, the current density of the lipid‐covered catalyst is enhanced without altering its core molecular structure. This electrochemical platform will help identify optimal thermodynamic and kinetic parameters for ORR catalysts and catalysts of other reactions that involve the transfer of both protons and electrons. [ABSTRACT FROM AUTHOR]

Molecular switches gate many fundamental processes in natural and artificial systems. Here, we report the development of an electrochemical platform in which a proton carrier switches the activity of a catalyst. By incorporating an alkyl phosphate in the lipid layer of a hybrid bilayer membrane, we regulate proton transport to a Cu-based molecular oxygen reduction reaction catalyst. To construct this hybrid bilayer membrane system, we prepare an example of a synthetic Cu oxygen reduction reaction catalyst that forms a self-assembled monolayer on Au surfaces. We then embed this Cu catalyst inside a hybrid bilayer membrane by depositing a monolayer of lipid on the self-assembled monolayer. We envisage that this electrochemical system can give a unique mechanistic insight not only into the oxygen reduction reaction, but into proton-coupled electron transfer in general. [ABSTRACT FROM AUTHOR]