Synergistic Contribution of the Acidic Metal Oxide–Metal Couple and Solvent Environment in the Selective Hydrogenolysis of Glycerol: A Combined Experimental and Computational Study Using ReOx–Ir as the Catalyst

Abstract

Comprehensive mechanistic insights into the aqueous-phase hydrogenolysis of glycerol by the ReOx–Ir catalyst were obtained by combining density functional theory (DFT) calculations with batch reaction experiments and detailed characterization of the catalysts using X-ray diffraction, X-ray photoelectron spectroscopy, and Fourier transform infrared techniques. The role and contribution of the aqueous acidic reaction medium were investigated using NMR relaxometry studies complemented with molecular dynamics and DFT calculations. At higher glycerol concentration, the enhanced competitive interaction of glycerol with the catalyst improved the conversion of glycerol. Sulfuric acid increased the concentration of glycerol within the pores of the catalyst and enhanced the propensity for dissociative adsorption of glycerol on the catalyst, explaining the promotional effect of acid during hydrogenolysis. Partially reduced and dispersed Bronsted acidic ReOx clusters on metallic Ir nanoparticles facilitated dissociat...