MOF-derived CuNi-doped RuO2 electrocatalyst with abundant oxygen vacancies for the oxygen evolution reaction in PEM water electrolysis

A Cu and Ni co-doped RuO2 (CuNi-RuO2) catalyst was optimized for the oxygen evolution reaction (OER) occurring in polymer electrolyte membrane water electrolysis. Using an octahedral CuNi-BTC MOF as a precursor, the cation exchange of Cu2+ and Ni2+ with Ru3+ enhanced the structural characteristics of the catalyst, including its surface area, porosity, and formation of a highly active RuO2 phase. Advanced spectroscopic analyses, including ESR and XPS, revealed that the integration of Cu and Ni facilitated the creation of oxygen vacancies within the RuO2 lattice and optimized the electronic environment at the Ru centers, increasing the catalytically active sites and overall catalytic activity. The CuNi-RuO2 catalyst demonstrated superior OER activity and durability under acidic conditions compared to those of its single-metal-doped counterparts and undoped RuO2. This study highlights the criticality of controlled synthesis conditions on MOF-derived catalysts performance, positioning CuNi-RuO2 as an efficient catalyst for OER in water electrolysis technologies.