Highly stable RuO₂/SnO₂ nanocomposites as anode electrocatalysts in a PEM water electrolysis cell

This work explores the opportunity to reduce the cost and enhance the stability of RuO₂ as an oxygen evolution reaction catalyst by coating RuO₂ on chemically stable SnO₂ support. Nano-sized RuO₂/SnO₂ composites of different mass ratios of RuO₂ to SnO₂ (0.45:1, 0.67:1, and 1.07:1) were synthesized using solution-based hydrothermal method. The physicochemical properties of the RuO₂/SnO₂ were studied by scanning electron microscopy, X-ray diffraction, transmission electron microscopy, and N₂ adsorption-desorption isotherms. The electrochemical activity of RuO₂/SnO₂ as anode electrocatalyst was investigated in a proton exchange membrane (PEM) water electrolysis cell of Pt/C cathode and Nafion membrane. Experimental results showed that RuO₂/SnO₂ of ratio (1.07:1) exhibit higher electrochemical activity compared to pure RuO₂, resulting ~50% reduction of noble metal content. The extended life test of electrocatalysts for 240 h implied that RuO₂/SnO₂ (1.07:1) significantly improved the stability of electrode in comparison to pure RuO₂ in oxygen evolution processes.