First-Principles Investigation of Hydroxyl Species Formation on β-MnO2(110) for Catalytic Oxidation Applications

Abstract

Hydroxyl (OH) species play a critical role in several oxidative catalysis processes, including the oxidation of 5-hydroxymethylfurfural (HMF) to produce valuable compounds like 2,5-furandicarboxylic acid (FDCA). High OH coverage on metal oxide surfaces significantly enhanced catalytic activity. Herein, we investigated OH coverage on the β-MnO₂(110) surface generated through the decomposition of oxidant molecules (O₂, H₂O₂, and tert-butyl hydroperoxide, TBHP) using density functional theory (DFT) calculations and ab initio thermodynamic modeling. We studied the kinetics and thermodynamics aspects of OH formation pathways, focusing on direct O–O and C–O bond cleavages and reactions with H₂O, both in gas and solvent environments. Computations reveal that TBHP and H₂O₂ exhibit lower dissociation barriers and favorable thermodynamics than O₂, yielding higher OH coverage under relevant reaction conditions. Phase diagrams constructed from thermodynamic models reveal that TBHP maintains high OH coverage across a broader temperature range, suggesting its potential as an efficient oxidant for catalytic applications. These insights support the development of β-MnO₂ catalysts tailored for oxidation processes by guiding oxidant selection and reaction conditions.