Silicon-doped niobium suboxide (NbOS): A fuel cell electrocatalyst support with enhanced conductivity and corrosion-resistance

Abstract

A novel carbon-free silicon-doped niobium suboxide was synthesized and tested as an electrocatalyst support for fuel cell applications. The promising Nb0·24O0·46Si0.30 (NbOS) metal oxide support exhibits a low structural band-gap with significantly high electronic conductivity. Furthmore, the NbOS support shows high corrosion-resistance in acidic media at high potentials. Pt nanoparticles were dispersed over the NbOS support (Pt/NbOS) to create an electrocatalyst with excellent electroactivity towards the oxygen reduction reaction (ORR). Likewise, in situ electrochemical analysis, and impedance spectroscopy (EIS) confirmed remarkable durability of the Pt/NbOS catalyst when subjected to harsh accelerated stress testing (AST) condtions. The enhanced stability and electrocatalytic activity and of Pt/NbOS is attributed to the strong metal-support interaction (SMSI) between the Pt nanoparticles (NPs) and the conductive NbOS support, which were confirmed via XRD and XPS measurements.