Enhanced Thermocatalytic Stability by Coupling Nickel Step Sites with Nitrogen Heteroatoms for Dry Reforming of Methane

Abstract

Ni-catalyzed dry reforming of methane is usually subjected to coke-induced instability due to an epitaxial lattice match between carbon and Ni step edge that stabilizes the carbon nucleus. Herein, we propose an innovative strategy through coupling Ni step-edge sites with N-heteroatoms to prevent the carbon nucleation. The N-heteroatoms preferentially are coupled at the Ni step sites, and the coupling effect attenuates the generation and adsorption of carbon intermediates via directionally regulating the d-band center of Ni-atoms around the step sites and further inhibits the carbon nucleation and growth. Moreover, the Ni step sites with N coverage accelerate the gasification rate of carbon with CO2, which further restrains the carbon deposition and substantially improves the catalytic stability for methane dry reforming.