Hydrodeoxygenation of m -Cresol Over Pt-WO x /C Using H 2 Generated In Situ by n -Hexane Dehydrogenation

Hydrodeoxygenation (HDO) of m -cresol using H 2 produced by dehydrogenation of n-hexane to hexenes is demonstrated at 673 K over a Pt-WO x /C catalyst at 36 bar. The reaction is possible because deactivation of Pt/C during n-hexane dehydrogenation is greatly suppressed at higher pressures. Flow-reactor measurements of pure n -hexane over Pt/C showed rapid deactivation at 1 bar and 773 K but the catalyst was stable for at least 5 h at 36 bar. While the Pt/C catalyst showed poor activity for HDO of m -cresol, the Pt-WO x /C catalyst was able to utilize the H 2 to selectively catalyze m -cresol to toluene, simultaneously pushing the conversion of n-hexane above the equilibrium value that would be achieved in the absence of H 2 consumption. To explain the increased stability for alkane dehydrogenation at higher pressures, a microkinetic model of propane dehydrogenation, a surrogate of hexane, was analyzed. The model demonstrates that the coverage of vacancies increases with increasing pressure at the expense of species believed to be coke precursors. Graphic Abstract