Benzyl alcohol to benzaldehyde oxidation on MnOx clusters: Unraveling atomistic features

• Catalytic oxidation of benzyl alcohol to benzaldehyde over MnO x catalysts is analyzed in the DFT framework. • Oxidation reactivity and selectivity over cluster-sized Mn 4 O 8 and Mn 4 O 9 catalytic models is compared. • Catalyst poisoning is addressed by investigating the formation of benzoic acid following that of benzaldehyde. • Reaction steps and the related oxidation pathways are collected and analyzed by an original kinetic approach. • Experimental strategies aimed at decreasing catalyst deactivation hence at increasing selectivity are proposed. The catalytic oxidation of benzyl alcohol with O 2 is a promising option for the production of benzaldehyde, from both environmental and economical viewpoints. In particular, highly dispersed MnO x systems feature good activity and selectivity in a wide range of temperatures, although deactivation phenomena by over-oxidation and/or poisoning of active sites are generally recorded. On this account, a density functional theory study was performed on cluster-sized catalyst models, namely Mn 4 O 8 and over-oxygenated Mn 4 O 9 fragments, to predict the reactivity pattern of MnO x catalysts in the selective aerobic oxidation of benzyl alcohol. Several pathways concur to determine the whole reaction process and all of them were compared to unveil the atomistic details of the alcohol oxidation mechanism. Moreover, assuming that the consecutive formation of benzoic acid affects the activity-stability pattern of the MnO x based catalyst, also the benzaldehyde oxidation mechanism was computationally addressed. A systematic comparison of the benzyl alcohol and benzaldehyde oxidation mechanisms on the Mn 4 O 8 and Mn 4 O 9 fragments reveals some experimental strategies to test the reaction mechanisms and design alternative catalytic routes to decrease undesired parasitic reactions leading to catalyst deactivation. The matching structural, energetic and kinetic data are published in the Data in Brief journal [1].