Pd-Catalyzed Dehydrogenation Enhanced by Charge Transfer from MoOx Promoter

Abstract

Incorporating metal oxides is a sensible strategy for enhancing the efficiency of precious metals. Upon the introduction of molybdenum oxide, diverse coordination structures were formed on the support surface depending on the concentration used. This modified surface architecture orchestrates consequential alterations in the electronic and geometric configurations of the active metal, concurrently influencing the catalytic performance. In this study, MoO x species were introduced into Pd in a controlled manner to substantially enhance the dehydrogenation activity of the N-heterocyclic liquid organic hydrogen carrier system. Pd-MoO x /Al2O3 catalyst-featuring an optimal 0.18 wt % Mo loading-demonstrated noteworthy improvement in activity, surpassing Pd/Al2O3 by factors of 1.57 and 1.24, accompanied by enhanced recyclability in two distinct LOHC systems. Integrated characterization and theoretical calculations elucidated the modification of the electronic properties of both Pd and Al2O3 upon MoO x introduction and the corresponding adsorption behavior of the reactants, highlighting the charge transfer phenomenon from Pd to MoO x .