Enhancing the acidic oxygen evolution reaction performance of RuO2-TiO2 by a reduction-oxidation process

Abstract

Abstract As a promising alternative to Ir based acidic oxygen evolution reaction (OER) catalysts, Ru suffers from severe fading issues. Supporting it on robust oxides such as TiO2 is a simple and effective way to enhance its lifetime. Here, we find that a simple reduction-oxidation process can further improve both activity and stability of RuO2-TiO2 composites at high potentials. In this process, the degree of oxidation was carefully controlled to form Ru/RuO2 heterostructure to improve OER activity. Moreover, due to the oxophilicity difference of Ru and Ti, the structure of catalysts was changed from supported to embedded, which enhanced the protective effect of TiO2 and mitigated the dissolution of Ru element in acidic electrolyte, making as-prepared Ru/RuO2-TiO2 with better durability at all tested potentials.