Optimization of Pt infiltrated Sr2Fe2-xMoxO6-δ-Ce0.8Sm0.2O1.9 oxygen electrode for reversible solid oxide cell and CH4-assisted electrolysis process

Abstract

Sr2Fe2-xMoxO6-δ-Ce0.8Sm0.2O1.9 (SFM-SDC) is a promising composite oxygen electrode for reversible solid oxide cells. In this study, well-dispersed Pt nanoparticles are prepared by one-cycle infiltration method using H2PtCl6 aqueous solution in SFM-SDC scaffold, to form high electrocatalytic activity Pt-SFM-SDC electrode for fuel cell, steam electrolysis and CH4-assisted steam electrolysis processes. Systematic studies in concentration variation of H2PtCl6 solution demonstrate that the discharge current of the 3.14 cm2 cell infiltrated by 0.040 M solution is significantly increased from 0.4 to 1.32 A (>3 times) at 0.5 V at 800 °C while the electrolysis current is effectively enhanced from 0.8 to 3.28 A (>4 times) at 1.5 V. Moreover, cells with Pt-SFM-SDC electrode applied in CH4-assisted electrolysis process realized a remarkable reduction of power consumption. Impedance analysis and morphological observation results suggest that appropriate H2PtCl6 concentration has a positive effect on surface exchange and gas diffusion process at oxygen electrode side.