Synthesis of highly porous LaCoO3 catalyst by Nanocasting and its performance for oxygen reduction and evolution reactions in alkaline solution

Abstract

Highly porous LaCoO3 perovskite was synthesized by a nanocasting method using a mesoporous silica template and subsequently applied as a bifunctional catalyst for the oxygen reduction and evolution reactions in alkaline solution. The La-Co citrate complex was mixed a porous SBA-15 silica template, and then, calcinated at 650 °C to prepare a LaCoO3/SBA-15 composite. Highly porous LaCoO3 was prepared by treating this composite with NaOH to remove the SBA-15 silica template. The obtained LaCoO3 showed a very rough surface, high surface area, and relatively small particle size compared with LaCoO3 prepared by the sol-gel method. The catalytic performance of the highly porous LaCoO3 for the oxygen reduction and evolution reactions was electrochemically measured in alkaline solution. LaCoO3 prepared by the nanocasting exhibited higher cell performance than that prepared by sol-gel method due to its larger surface area.