Catalytic Oxidation of Benzyl Alcohol Over Mno2 : Structure-Activity Description and Reaction Mechanism

Activity evaluation of metal oxide catalysts with different crystal structures has been an important prerequisite for industrial applications. This work systematically elucidates the structure-activity relationship of α-, β-, γ- and δ-MnO 2 catalysts toward the selective oxidation of benzyl alcohol (BA) to benzaldehyde (BAD). Exposed surfaces of MnO 2 are evaluated by a combined theoretical and experimental investigation. On this basis, a catalytic activity descriptor is established considering the surface energies, formation energies of oxygen vacancies (OVs), O 2 adsorption energies, and areal densities of OVs and unsaturated Mn. Inspired by this, we fabricate β-MnO 2 with a high surface area and it delivers the highest BA conversion among all MnO 2 . Furthermore, a developed Mars-van Krevelen mechanism is proposed to describe the BA oxidation process on the β-MnO 2 (110) surface. The research paradigm opens a door to the rational design of metal oxide catalysts