A study on the deactivation of nickel-based catalyst for the dry reforming of methane via density functional theory

Abstract

In this work, the stability assessment of catalyst for the dry reforming reaction was investigated through the coke resistance performance and the ability of coke removal. The coke resistance performance was considered via the coke adsorption energy. For surface 100 and 211, NiCo bimetallic catalyst and Ni exhibit weaker bonding between coke and catalyst surface. For surface 111, both catalysts exhibited similar adsorption energy value. NiCo bimetallic catalyst also showed higher adsorption energy for surface 111 and 211 than the noble metal catalyst such as Rh and Pd catalyst which means NiCo catalysts can show the coke resistance performance that is comparable with the noble metal catalyst. The ability of coke removal was investigation through the activation of the coke movement on catalyst surface or coke diffusion from the most stable active site to another stable active site. For surface 100 of Ni and NiCo catalyst, there is only one stable active site that refers to there is no coke movement on surface 100. For surface 111 and 211, NiCo catalyst shows lower activation energy of coke movement than Ni catalyst that translates NiCo is the better performance catalyst for coke removal.