Hydrodeoxygenation of anisole over Pt/Al‐SBA‐15: metal‐acid synergy

Hydrodeoxygenation (HDO) is a promising technology to upgrade fast pyrolysis bio‐oils but requires active and selective catalysts. Here we explore the synergy between metal and acid sites in the HDO of anisole, a model pyrolysis bio‐oil compound, over mono‐ and bifunctional Pt/(Al)‐SBA‐15 catalysts. Ring hydrogenation of anisole to methoxycyclohexane occurs over metal sites and is structure sensitive, being favored over small (4 nm) Pt nanoparticles which confer a turnover frequency (TOF) of ~2000 h‐1 and methoxycyclohexane selectivity of ~90 % at 200 °C and 20 bar H2; in contrast, formation of benzene and the desired cyclohexane product appears structure insensitive. Introduction of acidity to the SBA‐15 support promotes demethyoxylation of the methoxycyclohexane intermediate, increasing the selectivity to cyclohexane from 15 % to 92 % and 6 h cyclohexane productivity by two orders of magnitude (from 15 mmol.gPt‐1.h‐1 to 6500 mmol.gPt‐1.h‐1). Optimizing the metal‐acid synergy confers an 865‐fold increase in cyclohexane production per gram Pt and 28‐fold reduction in precious metal loading. These findings demonstrate that tuning the metal‐acid synergy provides a strategy to direct complex catalytic reaction networks and minimize precious metal use in biofuels production.