Reaction environment impacts charge transfer but not chemical reaction steps in hydrogen evolution catalysis

Differentiating Oxygen Exchange Reaction Mechanisms across Phase Boundaries

“…Our methodology is based on operando EIS performed under realistic reaction conditions with variable applied biases rather than limited to quasi-equilibrium conditions. Our insights might be useful for evaluating the overpotential contributed by the change of chemical composition or phase transition, similar to the recent findings in PdH x -based electrocatalysts . Another potential area of impact might be the design of materials for emerging electrochemical ionic synaptic devices, , where the coupled ionic and electronic transfer (CIET) governs the operation speed.…”

Developing electrochemical hydrogenation towards industrial application

“…This approach does not only take advantage of the well-known ability of Pd to perform hydrogenation reactions, but also its ability to transport hydrogen atoms through the Pd lattice, to effectively separate an aqueous environment providing protons from the organic hydrogenation compartment, which enables the use of organic solvents for the hydrogenation of hydrophobic organic substrates. This separation also facilitates the investigation of underlying mechanisms and electrocatalytic screenings via metal sputtering methods, 38,42,43 permits the efficient deuteration of organic compounds 44 as well as the regeneration of enzymatic cofactors. 40 Further groups have adopted this design, with Zhang et al expanding the approach for the conversion of acetonitrile to ammonia, 45 Xu et al applying this reactor design for reductive treatment of halogen-containing contaminants in water, 46 and Sun and coworkers even enabled a highly efficient dual hydrogenation by applying Pd-membranes not only as the cathode but also as the anode for formaldehyde oxidation.…”

Minireview of the Electrocatalytic Local Environment in Alkaline Hydrogen Evolution

“…Also, many reports have proven that the core–shell-structured Pt catalyst (e.g., Ru@Pt) has an even better performance than the PtRu alloy, which is also contradictory to the “dual-site” theory. − Obviously, besides the intermediate adsorption behavior of the catalyst, there are other factors that significantly alter the reaction mechanism of the alkaline HER that need to be unveiled. New evidence found recently has proven that the pH only impacts the kinetics by affecting the charge transfer potential during the HER and not the chemical reaction process . Such findings suggest that, to find the origin of the sluggishness of alkaline HER, it is necessary to dig into the electrocatalytic interface with in situ methods to investigate details, such as local pH, molecule configuration, and cation transfer, as well as other local environmental influences.…”