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

• Published in: Catalysis today Vol. 172; no. 1; pp. 103 - 110
• Main Authors: Loricera, C.V., Pawelec, B., Infantes-Molina, A., Álvarez-Galván, M.C., Huirache-Acuña, R., Nava, R., Fierro, J.L.G.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 25-08-2011; Elsevier
• Subjects: acidity; Anisole; Catalysis; catalysts; catalytic activity; Chemistry; Cobalt–molybdenum–tungsten; Colloidal state and disperse state; combustion; Exact sciences and technology; General and physical chemistry; Hydrodeoxygenation; hydrogen; Hydrotreatment; isomerization; o-cresol; oils; phenol; Phosphate; Porous materials; pyrolysis; SBA-15; SBA-16; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; SBA-16; Cobalt–molybdenum–tungsten; Hydrodeoxygenation; Hydrotreatment; Anisole; Phosphate; SBA-15; Phosphates; Modification; Support; Hydrogen; Coke; Combustion; X ray; Cobalt; Porous material; Supported catalyst; Model compound; Tungsten; Cobalt-molybdenum-tungsten; Photoelectron spectrometry; Pyrolysis; Catalytic reaction; Stability; Hydrogenolysis; Catalyst selectivity; Transition metal; X ray diffraction; Molybdenum; Steady state; Mesoporosity; Ammonia; Heterogeneous catalysis; Oil; Transmission electron microscopy; Gas phase; Catalyst
• ISSN: 0920-5861; 1873-4308
• DOI: 10.1016/j.cattod.2011.02.037

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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.
This contribution describes the effect of SBA-15(16) support modification with variable quantity of P
2O
5 (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 (
S
BET, XRD, TPD-NH
3, 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)S
2 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.