3D nitrogen-doped carbon supported non-precious metals electrocatalyst for oxygen reduction reaction

Abstract

Sluggish oxygen reduction reaction (ORR) is a rate-limiting step in some electrochemical devices such as fuel cells. Thus, the synthesis and development of high performance, inexpensive and durable catalysts for ORR is a necessity. Metallic nanostructures decorated heteroatoms-doped carbons have been recognized as excellent catalysts in energy applications. However, nitrogen-doped partially oxidized three-dimensional carbonaceous supports were seldom studied for ORR. Herein, the synthesis of low Fe-Co bimetallic contents deposited on three-dimensional (3D) activated carbon (AC) is reported as an efficient and cost-effective catalyst for ORR in alkaline electrolyte. In the present work, AC was thermally treated by direct heat in air at 430 °C to enhance its electrochemical activity through increasing structure deficiency. AC and nitrogen doped AC (N-AC) were used to synthesize Fe-Co/AC and Fe-Co/N-AC. In both Fe-Co/AC and Fe-Co/N-AC, low amounts of non-precious Fe and Co nanoparticles were deposited on carbonaceous substrates. The air oxidation process, for partially oxidation of carbon structure and catalyst post treatment, was used for introducing defects to the catalyst structure. The performance of synthesized samples was evaluated by ORR process in alkaline medium.