High Surface Area Mo2N:Novel Durable Support for Fuel Cell Electrocatalysts

摘要

In recent years, fuel cell technology has received much attention as a promising avenue for providing sustainable energy. However, high costs associated with fuel cell catalysts, as well as the durability of these materials, have proven to be a substantial economic constraint. Of particular interest is the low durability of state-of-the-art Pt/C catalysts due to electrochemical oxidation, and subsequent corrosion, of the carbon support [1]. As such, it has been proposed to replace carbon with alternative, high surface area, materials such as transition metal oxides and nitrides, which possess high electrical conductivity and corrosion resistant properties under PEMFC operating conditions [2]. Molybdenum nitride supported on high surface area carbon has been shown to have catalytic activity in oxygen reduction (ORR) comparable to Pt/C [3], which suggests that Mo2N as an ORR catalyst support may enhance fuel cell performance through a promotion effect. In this work we present the synthesis and characterization of high surface area Mo2N prepared by sacrificial support method (SSM) [4]. Ammonolysis of various Mo precursors were studied and the reaction pathways, through both a MoO2 intermediate and a direct route to Mo2N, are compared.