析氧反应中催化剂-电解质界面的质子动力学研究

电催化水分解是一种可持续的绿色产氢技术,该技术在工业化的大规模应用急需开发高效稳定的非贵金属催化剂,用于提高析氧反应(OER)的反应速率.研究发现,钙钛矿氧化物是优异的OER催化剂,但是对于发生在催化剂-电解质固液界面上的反应机理仍有争论.目前普遍认为,在OER反应过程中,水分子吸附在金属氧化物催化剂表面的金属活性中心...

The role of proton dynamics on the catalyst-electrolyte interface in the oxygen evolution reaction

The development of non-precious metal catalysts that facilitate the oxygen evolution reaction (OER) is important for the widespread application of hydrogen production by water splitting. Various perovskite oxides have been employed as active OER catalysts, however, the underlying mechanism that occurs at the catalyst-electrolyte interface is still not well understood, prohibiting the design and preparation of advanced OER catalysts. Here, we report a systematic investigation into the effect of proton dynamics on the catalyst-electrolyte interfaces of four perovskite catalysts: La0.5Sr0.5CoO3-δ (LSCO), LaCoO3, LaFeO3, and LaNiO3. The pH-dependent OER activities, H/D kinetic isotope effect, and surface functionalization with phosphate anion groups were investigated to elu-cidate the role of proton dynamics in the rate-limiting steps of the OER. For oxides with small charge-transfer energies, such as LSCO and LaNiO3, non-concerted proton-coupled electron transfer steps are involved in the OER, and the activity is strongly controlled by the proton dynamics on the catalyst surface. The results demonstrate the important role of interfacial proton transfer in the OER mechanism, and suggest that proton dynamics at the interface should carefully be considered in the design of future high-performance catalysts.