In Operando Investigation of the Role of Solid-Liquid Interface towards Stability of Electrocatalysts

Abstract

To pursue a sustainable energy society, electrochemical energy conversion has been perceived as a key for the future energy scenario. Electrocatalysis, therefore, is at the core of its successful implementation. Over the last years, progress has been made in the catalytic performance by engineering physicochemical properties of catalyst (e.g., doping, alloying, modifying nanostructures, etc.). Recently, its significant advance has been further achieved by virtue of the solid-liquid interface engineering, accomplished by tuning interfacial components such as solvent, reactant, pH, identity/activity of ionic species, etc. Hence, numerous experimental and computational investigations have been conducted, on the one hand, to upgrade catalytic activity/selectivity and, on the other hand, to elucidate fundamental details. Although stability is also one of the essential components of electrocatalysis, however, the effects of the solid-liquid interface on stability have been rarely investigated so far. Herein, we investigate the effect of the interfacial components such as reactant, surface structure, and identity of ionic species on the catalyst stability using advanced spectroscopic analyses with a model electrocatalyst, platinum. The Pt stability is significantly influenced by these interfacial parameters resulting from a complex convolution of the substantial changes in surface chemistry (e.g., adsorption of reactants/reaction intermediates, instable Pt species, etc.) and electric double layer chemistry (e.g., complexation of dissolved Pt species, electric field, etc.). With these understandings, we discuss a concept-of-proof strategy for mitigating the Pt degradation.