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

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 Ni 3 ZnC 0.7 /Al 2 O 3 . This strategy can fundamentally avoid C−C bond formation and feasible oxidation of Ni 3 ZnC 0.7 in low-temperature DRM under CO 2 -rich condition. About 2 nm of thin-layer Al 2 O 3 encapsulated Ni 3 ZnC 0.7 is explored as the carbon reservoir to accommodate sufficient interstitial carbon atoms, and less than 5% Ni 3 Zn was observed under CH 4 /CO 2 < 1/1 for 100 h. The dynamic balance of carbon atom storage and conversion in robust Ni 3 ZnC 0.7 contributes to the enhanced activity, stability, coke and oxidation resistance, and distinct reaction pathway in low-temperature DRM. About 2 nm of thin-layer Al 2 O 3 encapsulated Ni 3 ZnC 0.7 with 54.4 wt% of Ni content is explored as carbon reservoir to accommodate sufficient carbon atoms in the interstitial sites, and effectively avoid the C−C bond formation and the catalyst oxidation during LT-DRM under a CO 2 -rich feed. • Core-shell Ni 3 ZnC 0.7 /Al 2 O 3 catalyst was designed for DRM. • Ni 3 ZnC 0.7 is explored as carbon reservoir for sufficient carbon atoms. • Ni 3 ZnC 0.7 /Al 2 O 3 exhibited superior activity and stability in CO 2 -rich conditions. • Ni 3 ZnC 0.7 /Al 2 O 3 tailored the evolution of carbon atoms under CH 4 /CO 2 < 1/1. • Carbon atom were stored and converted in interstitial sites in robust Ni 3 ZnC 0.7 /Al 2 O 3 .