Defect and interstitial B synergistically promote the stability and H2 dissociation of Pd6 supported by graphene

As a potential hydrogenation catalyst, palladium nanoparticles supported by graphene encounter three major problems: transition metal agglomeration, interstitial H atom, and the competition between desorption of H-2 and Pd-n-H-x complex from graphene sheet. In this paper, defects and interstitial B are used to promote the stability and H-2 dissociation of Pd6 supported by graphene. The introduction of defects increases the binding energy of Pd, Pd-6 and Pd6B to graphene by a factor of 5-7 and 7-9 before and after hydrogen adsorption, respectively. It indicates that defects can effectively avoid the desorption competition between PdnHx and hydrogen molecules. Moreover, the energy barrier of dissociation for the first hydrogen molecule on Pd6B/C-49 is 0.49 eV, which is lower than 0.75 eV on Pd-6/C-49 and 0.69 eV on Ti-6/C-49. (C) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.