Water Spillover to Expedite Two-Electron Oxygen Reduction.

Limited by the activity-selectivity trade-off relationship, the electrochemical activation of small molecules (like O, N and CO) rapidly diminishes Faradaic efficiencies with elevated current densities (particularly at ampere levels). Nevertheless, some catalysts can circumvent this restriction in a two-electron oxygen reduction reaction (2e ORR), a sustainable pathway for activating O to hydrogen peroxide (HO). Here we report 2e ORR expedited in a fluorine-bridged copper metal-organic framework catalyst, arising from the water spillover effect.

Pseudo-Jahn-Teller Effect Breaks the pH Dependence in Two-Electron Oxygen Electroreduction.

The hydrogenation of small molecules (like O and CO) often exhibits strong activity dependence on pHs because of discrepant proton donor environments. However, some catalysts can show seldom dependence on two-electron oxygen electroreduction, a sustainable route of O hydrogenation to hydrogen peroxide (HO). In this work, a pH-resistant oxygen electroreduction system arising from the pseudo-Jahn-Teller effect is demonstrated.

Single-zinc vacancy unlocks high-rate HO electrosynthesis from mixed dioxygen beyond Le Chatelier principle.

Le Chatelier's principle is a basic rule in textbook defining the correlations of reaction activities and specific system parameters (like concentrations), serving as the guideline for regulating chemical/catalytic systems. Here we report a model system breaking this constraint in O electroreduction in mixed dioxygen. We unravel the central role of creating single-zinc vacancies in a crystal structure that leads to enzyme-like binding of the catalyst with enhanced selectivity to O, shifting the reaction pathway from Langmuir-Hinshelwood to an upgraded triple-phase Eley-Rideal mechanism.

Tandem-Parallel Electrochemical Cells to Produce Hydrogen Peroxide at Reduced Energy Consumption.

Large-scale industrialization of oxygen electroreduction requires producing hydrogen peroxide (HO) at large yield rates (current density >1 A cm, Faradic efficiency >95%). Under such vigorous reaction conditions, however, serious electric energy consumption (EEC) has been caused. According to the formula (), a linear relationship can be identified between HO yield rates () and EEC, and therefore, achieving high yield rates () while reducing EEC is very challenging in common electrochemical systems.

Bioinspired inhibition of aggregation in metal-organic frameworks (MOFs).

Different from traditional procedures of using solid stabilizers like polymers and surfactants, here we demonstrate that water, as a very "soft" matter, could function as a "spacer" to prevent the aggregation of metal-organic frameworks (MOFs) in aqueous dispersions. Our theoretical calculations reveal in case of an excess of positively charged metal nodes of MOFs, where water molecules are ligated to metal nodes that greatly enhance MOFs' solution dispersibility through electrostatic stabilization. This discovery has motivated us to develop a facile experimental approach for producing a category of "clean" MOF dispersions without foreign additives.

Biomimetic FeMo(Se, Te) as Joint Electron Pool Promoting Nitrogen Electrofixation.

It has been long believed that the FeMoS structure, where Fe is bonded with S, plays a pivotal role as a biomimetic catalyst for electrochemical nitrogen (N ) fixation. Nevertheless, the structure of Fe bonded to heavier analogues (Se or Te) has never been explored for N electrofixation. Here, we theoretically predict the electronic structure of FeMo(Se, Te) composed of tri-coordinated Fe species with open shells for binding with Se, which forms a joint electron pool for promoting N activation.