Combining electrolysis with thermocatalysis for dry reforming of methane in a naturally stratifying liquid alloy-salt catalytic system

Abstract

Dry reforming of methane (CH4) with carbon dioxide (CO2) is an attractive technology for producing value-added syngas and mitigating greenhouse gas emission. However, this process usually requires high energy input due to the intrinsic inertness of CH4 and CO2. Besides, the widely investigated solid Ni-based catalysts typically suffer from coking and sintering issues, leading to degradation in catalytic performance. Liquid alloys and molten salts are emerging as promising catalytic materials for CH4 dry reforming. In this work, we combine electrolysis with thermocatalysis for CH4 dry reforming in a naturally stratifying liquid alloy-salt system, which achieves effective and stable catalytic performance under relatively mild operation conditions. The conversions of CH4 and CO2 reach 37% and 95%, respectively, in a bubble column reactor comprising Ni–Bi alloy and LiNaCO3 during constant current electrolysis at 1.5 A and 900 °C. The selectivities of H2 and CO were maintained at 85% and 92%, respectively. Ab initio molecular dynamics simulation shows that the oxides of both Ni and Bi promote the C–H bond dissociation. Therefore, the electrochemical process combine electrolysis with thermocatalysis in the liquid alloy-salt system represents a promising approach to achieving effective and stable CH4 dry reforming.