Zeolite-templated Ir_xRu_(1-x)O_2 electrocatalysts for oxygen evolution reaction in solid polymer electrolyte water electrolyzers

摘要

Ir_xRu_(1-x)O_2(l ≥ x ≥ 0) with nanorod structure were successfully synthesized by employed pre-filling the Ir and/or Ru guest species into the peripheral-pore of NH_2-modified as-synthesized SBA-15 and explored as electrocatalyst for oxygen evolution reaction (OER) in water electrolyzers. Various physicochemical parameters for zeolite template and/or Ir_xRu_(1-x)O_2 were obtained by SEM, TEM, XRD, EDX and N_2 gas absorption/desorption measurements. The morphology for prepared Ir_xRu_(1-x)O_2 samples with individual and/or cluster nanorods was changed with the component difference. Cyclic voltammetry, linear sweep voltammetry, electrochemical impedance spectroscopy, steady state polarization curves and stability tests were performed to investigate the catalytic activity and stability of these electrocatalysts for OER. The cell with catalyst RuO_2 showed best catalytic performance with the lowest onset potential (1.374 V at 10 mA cm~(-2)), which may be ascribed to regular nanoclusters and larger outer active surface area. Meanwhile, the cell stability tests suggested that the addition of IrO_2 in Ir_xRu_(1-x)O_2 improved the stability of the RuO_2 catalyst.