Three-dimensional ordered mesoporous Co₃O₄ enhanced by Pd for oxygen evolution reaction

Considerable efforts have been devoted recently to design and fabrication of high performance and low cost electrocatalysts for oxygen evolution reaction (OER). However, catalytic activity of current electrocatalysts is usually restricted by high onset potential and limited active sites. Herein, we fabricated three-dimensional (3D) highly ordered mesoporous Pd-Co₃O₄ composite materials as excellent electrocatalysts for OER in alkaline solution with high activity and stability. Three-dimensional highly ordered mesoporous Co₃O₄ material was firstly synthesized using mesoporous silica KIT-6 as hard template. Then, Pd-Co₃O₄ nanomaterials were prepared by a simple reduction method. The as-prepared 3D mesoporous Pd-Co₃O₄ catalysts have ordered mesoporous structure with a high surface area of 81.0 m² g^-1. Three-dimensional highly ordered mesoporous structure can facilitate diffusion and penetration of electrolyte and oxygen. Moreover, the catalysts can also keep catalyst particles in a well dispersed condition with more catalytic active sites. Electrochemical measurements reveal that the 3D mesoporous Pd-Co₃O₄ catalysts exhibit superior performance in alkaline solution with low onset potential (0.415 V vs. SCE) and excellent long-duration cycling stability.