Adsorption mediated tandem acid catalyzed cellulose hydrolysis by ortho-substituted benzoic acids.

[Display omitted] • Adsorption energies correlate with the catalytic activity of benzoic acid derivatives. • Protonated model allows the calculation of experimentally comparable parameters. • 2D Energy landscape shows higher dependence in the glyosidic bond dissociation. Carboxylic acid and phenol moiety containing carbon materials are proven to catalyze cellulose hydrolysis. Experiments utilizing benzoic acid and substituted derivatives as model catalysts revealed that vicinal oxygenated group containing catalysts showed significantly higher activities regardless of acidity. However, the increase in catalytic activity was not well understood. Using density functional theory, the mechanism of catalysis was elucidated. Calculated binding energy followed the experimental turnover number suggesting that the formation and the stability of the adduct complex is imperative to catalysis. In addition to this, protonated system effectively modeled the experimental activation energy implying that a hydronium participates in the reaction. These calculations indicated that during the life time of the adduct complex, a dissolved proton assists in the overall catalytic mechanism. [ABSTRACT FROM AUTHOR]