Understanding the effect of Ni cluster size on methane activation and dehydrogenation

The cluster size of the active metal of the catalyst has great effect on the carbon deposits during the dry reforming of methane. In this paper, the effect of active metal cluster size on methane activation and dehydrogenation is specifically studied. Three cluster models of Ni4, Ni9, and Ni16 are applied to study and simulate the activation and dehydrogenation process of CH4 on Ni clusters of different sizes. It is found that the adsorption energy of CH4 on Ni clusters increases with the increase of cluster size, but it is fairly close. The adsorption energies of CH3, CH2, CH and C are the largest on Ni9. In this process, electrons are always transferred from Ni clusters to adsorbents, and the amount of electron transfer is proportional to the adsorption energy. In the CH4 dehydrogenation process, Ni16 showed the most excellent activity and anti-carbon performance.(c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

The cluster size of the active metal in the catalyst significantly affects the carbon deposits in the dry reforming of methane. This paper specifically investigates the effect of active metal cluster size on methane activation and dehydrogenation. Three cluster models of Ni4, Ni9, and Ni16 were used to study and simulate the activation and dehydrogenation process of CH4 on Ni clusters of different sizes. It was found that the adsorption energy of CH4 on Ni clusters increases with cluster size, but the difference is relatively small. The adsorption energies of CH3, CH2, CH and C are highest on Ni9. Electron transfer from Ni clusters to adsorbents always occurs in this process, and the amount of electron transfer is proportional to the adsorption energy. Ni16 exhibited the most excellent activity and anti-carbon performance in the CH4 dehydrogenation process.