Exploiting RuNi mixed oxide solid solution to synthesize a RuNi alloy with lattice strain as an active electrocatalyst for producing hydrogen in alkaline media

Abstract

Developing efficient and stable electrocatalysts is the key to realizing the scalable production of hydrogen through alkaline water electrolysis. Ruthenium (Ru) is a promising substitute for platinum (Pt), but the under-optimized Ru–H bond strength remains a major impediment to its practical application. Herein, we propose a new method for synthesizing a RuNi alloy by forming Ru–Ni mixed oxide solid solution first and reducing it in hydrogen to simultaneously transform Ru³⁺/Ni²⁺ into the RuNi alloy. Alloy-induced lattice strain and optimized electronic structure enable the modulation of the Ru–H bond strength and a significant improvement of HER activity. The optimized catalyst exhibits remarkable performance with a low overpotential of 34 mV at 10 mA cm⁻² and excellent stability for 90 h without notable performance degradation.