Theoretical study on dry reforming of methane catalyzed by Cu12M (M = Cu, Fe, Co, Ni) core-shell bimetallic clusters

Abstract Dry reforming of methane (DRM) reaction can not only effectively solve the greenhouse effect, but also produce H2 and CO, which are important raw materials and intermediates for Fischer-Tropsch synthesis. In this paper, the mechanism of DRM on Cu12M (M = Cu, Fe, Co, Ni) core-shell bimetallic nanoclusters was studied by density functional theory (DFT). The Mulliken charge distribution indicates that the charge in the core-shell structure is transferred to the shell atom (Fe, Co, Ni) through the core atom (Cu). The results of binding energy and bond length indicate that Fe, Co and Ni as core atoms enhance the structural stability of Cu13 nanoclusters. The analysis of partial density of states (PDOS) and d-band center indicates that Cu12Ni is the most potential DRM catalyst due to the highest electronic activity. The mechanism study shows that Cu13, Cu12Co and Cu12Ni all react in the same path, while Cu12Fe takes another route. The rate-determining step is CH3* → CH2* + H*, and the total energy barrier of DRM on Cu12Ni nanocluster is relatively the lowest, which is the most cluster to catalytic DRM reaction.