Effect of interstitial carbon atoms in core-shell Ni3ZnC0.7/Al2O3 catalyst for high-performance dry reforming of methane

Abstract

Dry reforming of methane (DRM) on Ni-based catalysts provides an economically and environmentally pivotal route to generate synthesis gas. However, coke formation on Ni surface by the growth of carbon atoms is the main reason for catalyst deactivation and reactor blockage. Here, we propose a reaction-induced method to incorporate and store active carbon atoms into nickel octahedral sites in core-shell Ni3ZnC0.7/Al2O3. This strategy can fundamentally avoid C−C bond formation and feasible oxidation of Ni3ZnC0.7 in low-temperature DRM under CO2-rich condition. About 2 nm of thin-layer Al2O3 encapsulated Ni3ZnC0.7 is explored as the carbon reservoir to accommodate sufficient interstitial carbon atoms, and less than 5% Ni3Zn was observed under CH4/CO2 < 1/1 for 100 h. The dynamic balance of carbon atom storage and conversion in robust Ni3ZnC0.7 contributes to the enhanced activity, stability, coke and oxidation resistance, and distinct reaction pathway in low-temperature DRM.