Tailoring B-site of lead-ruthenate pyrochlore for boosting acidic water oxidation activity and stability

Abstract

Achieving highly active, stable and low cost oxygen evolution reaction (OER) catalysts is a significant challenge for promoting splitting water technology in acidic media. Herein, we report a low-temperature pyrolysis cation exchange resin (CER) strategy to synthesize lead-ruthenate pyrochlore (Pb2[Ru2−xPbx]O7-δ) catalyst with different contents of Pb substituted at B-site. We demonstrated temperature effectively influence the amount of Pb at B-site, further modulated the electronic states of Ru and the concentration of oxygen defects. Benefiting from rich oxygen defects, the representative PRPO-350 catalyst exhibits outstanding OER activity with a overpotential of 174 mV at 10 mA cm−2geo, a super-low Tafel slope of 28.8 mV dec-1 and excellent stability up to 150 h in acid water. DFT calculations have demonstrated that the such structure will lead to the O-2p orbital closing to the Fermi level, eventually boosts the OER activity.