Hydrogenolysis of anisole over mesoporous sulfided CoMoW/SBA-15(16) catalysts

This contribution describes the effect of SBA-15(16) support modification with variable quantity of P2O5 (0.5 and 1.0 wt%) on the catalytic response of supported ternary CoMoW catalysts tested in the gas-phase hydrogenolysis of anisole, as a model compound for pyrolysis oil. The catalysts were characterized by a variety of techniques (SBET, XRD, TPD-NH3, XPS, HRTEM and coke combustion followed by TG/DTG). Under steady-state conditions, the sulfided CoMoW/SBA-16 catalyst modified with a small amount of phosphate (0.5 wt%) recorded the highest activity and stability in anisole transformation at 310 °C and 3 MPa of hydrogen pressure. All catalysts exhibited similar selectivities at the same anisole conversion (38%), indicating that catalyst morphology did not influence the catalytic behavior. Regardless of the carrier, deoxygenation was not significant, with demethylation (phenol) and isomerization (o-cresol, o-xylenol) being the main reaction routes. The highest activity recorded by the phosphate-containing CoMoW/SBA-16 catalyst is associated with its highest total acidity, the largest population of Mo(W)S2 phases located mainly within the inner support porous structure, the greatest sulfidation degree of W species and major stability during time-on-stream operation with respect to other catalysts.

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► The mechanism of anisole transformation over SBA-15(16)-based sulfide Co–Mo–W catalysts is bifunctional, with a major contribution of the acidic function.
► Metal sulfides are better dispersed on SBA-16 than on the SBA-15 substrate.
► The addition of 0.5 wt% of phosphate generates the largest population of active sites, the highest total acidity and best stability during on-stream condition.