Tailoring Ni-based catalyst by alloying with transition metals (M = Ni, Co, Cu, and Fe) for direct hydrocarbon utilization of energy conversion devices.

Abstract

There is increasing demand for versatile catalysts for direct hydrocarbon utilization with the coming of hydrocarbon economy. The catalysts are required to possess both high catalytic activities and excellent carbon coking tolerance for the hydrocarbon oxidation process. In this regard, we considered Ni-based alloy catalysts, e. g. Ni-Co, Ni-Cu, and Ni-Fe, which are expected to provide synergistic effects from the high catalytic activities of Ni and the high carbon coking tolerance of transition metals. We conduct a systematic investigation of catalytic effects on the electrochemical properties and the carbon coking tolerance of the candidates. Moreover, the binding strengths of H,O, and C species with each alloy catalyst were examined via density functional theory (DFT) calculations, providing insight into the trend of catalytic activity and carbon coking tolerance. In this study, the single cell for the solid oxide fuel cell with Ni-Fe catalyst shows the best electrochemical performance, 0.81 and 0.30 W cm (2) at 700 degrees C under H2 and C3H8, respectively, with excellent tolerance against carbon deposition.