An ONIOM investigation of reaction mechanisms of propylene glycol dehydration over H-ZSM-5 and H-MOR catalysts

The reaction mechanisms for dehydration of propylene glycol (1,2-propanediol) to propanone and propanal over the H-ZSM-5 and H-MOR catalysts have been theoretically studied using ONIOM(MO:MO) approach. The H-ZSM-5 and H-MOR catalysts modeled as 52T and 68T clusters were employed in the ONIOM(B3LYP/6-31+G(d):AM1) method. For the reaction either over the H-ZSM-5 or H-MOR catalysts, four steps for the propylene glycol conversion to propanone and three steps for the conversion to propanal were found. Thermodynamic properties, rate and equilibrium constants of these reactions are reported.

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (190 K)Download as PowerPoint slideHighlights► Propylene glycol conversion over the H-ZSM-5 and H-MOR was studied. ► Two products of propylene glycol conversion were found as propanone and propanal. ► Thermodynamic properties of each reaction steps of catalytic reactions are reported. ► The overall reaction enthalpies of pathways on both catalysts are exothermic process.