Computational Insights into the Hydrodeoxygenation of Phenolic Compounds over Pt-Fe Catalysts

Density functional theory calculations were performed to study the adsorption and hydrodeoxygenation (HDO) of phenol,o-cresol, and guaiacol on Pt-Fe surfaces. The crucial impact of bimetallic Pt-Fe surface structures on the catalytic activity and selectivity was revealed. Key parameters in dictating the C_Ar-O bond cleavage activity across different phenolic reactants were identified. The phenolic hydroxyl group interacted with surface metal atoms to modify the C_Ar-O bond length and charges transferred from the catalyst surface to the related groups of phenolic reactants, thereby influencing the C_Ar-O bond cleavage properties. The dehydroxylation reactions ofo-cresol proceeded more easily on 1Pt_sub-Fe(211), while the C_Ar-O cleavage reaction of phenol was more likely to occur on 1Pt_ads-Fe(211). Based on the three possible paths of guaiacol conversion, phenol would be the major product on both the 1Pt_ads-Fe(211) and 1Pt_sub-Fe(211) surfaces, but its formation was from different pathways. Introduction of Pt in different forms leads to dissimilar structural and electronic effects on the adsorption as well as the HDO activity and selectivity.