Non-precious Metal Oxygen Reduction Reaction Catalysts Synthesized Via Cyanuric Chloride and N-Ethylamine

Abstract

Non-precious metal oxygen reduction reaction catalysts were synthesized in this study using novel and cheap nitrogen sources, cyanuric chloride, and N-ethylamine. These materials presented a promising catalytic activity toward the oxygen reduction reaction (ORR) in acid media, which is the most challenging. For the catalyst based on N-ethylamine, the onset potential for ORR is 0.803 V vs reversible hydrogen electrode (RHE) or 0.703 V at 0.1 mA cm−2. The nitrogen source is shown to be extremely important in the final morphology and ORR activity of the catalyst. Steady state ORR polarizations evidenced that the final morphology of the catalysts play a major rule on mass transport in this class of catalysts, with a lamella-like structure being detrimental. Physical characterizations of the catalysts revealed that cyanuric chloride promotes morphology alterations to the carbon support toward a lamella-like structure, while the catalysts synthesized from N-ethylamine retained the nanoparticle structure of the carbon precursor. This catalyst exhibited a Tafel slope of 66 mV per current decade in the lower potential region, with promising four-electron selectivity in a polymer electrolyte fuel cell (PEFC) operational potential.