Ni and Ru bimetal nanoparticles-anchored porous Mo2C nanorods used as an internal reforming catalyst layer for hydrocarbon-fueled solid oxide fuel cells

Abstract

Solid oxide fuel cells (SOFCs) are considered the most efficient technology for the direct conversion of hydrocarbons to electrical energy. Although the commonly used Ni/YSZ cermet materials in SOFCs show excellent electrocatalytic properties in H2 fuel, they suffer from carbon deposition problem when hydrocarbon fuels are used. In this work, we study the use of Ni0·05Ru0.05-Mo2C with a porous nanorod-shaped morphology as an internal reforming catalyst layer for methane-fueled SOFCs to solve the degradation of cell performance due to carbon deposition. The electrochemical performance and coking tolerance of two types of cells with and without the catalyst layer were systematically studied using methane and hydrogen as fuels. With the catalyst layer, the single cell using methane as fuel exhibits an improvement in peak power density by 24%, increasing from 297 to 367 mW cm−2 and there was no diffusion barrier for fuel gases within the cell. Furthermore, the cell can stably run for 100 h in methane at 700 °C. The improvement of electrochemical performance is attributed to the synergistic effect of Ni and Ru sites anchored on the porous Mo2C nanorods catalyst based on strong metal-support interactions, promoting the effective catalytic conversion of CH4 to CO and H2. This study demonstrates that the integration of a catalyst layer for internal reforming is an effective strategy for the direct use of methane in SOFCs.