Effect of H2S and CO on the transformation of 2-ethylphenol as a model compound of bio-crude over sulfided Mo-based catalysts: propositions of promoted active sites for deoxygenation pathways based on an experimental study

Hydrodeoxygenation of Phenolic Compounds by Sulfided (Co)Mo/Al2O3Catalysts, a Combined Experimental and Theoretical Study

“…Such a promoting effect was already reported in literature [14,15] and was attributed to a decrease of the metal-sulfur bond allowing an easier formation of sulfur vacancies (CUS), which are proposed as active sites for such a reaction [14, 15,[21][22][23], while maintaining an optimal metal-heteroatom bond energy [34]. Moreover, we can underline that the effect of Co depends on the involved deoxygenation route: the DDO pathway is promoted in a larger extent than the HYD pathway, whatever the phenolic reactant.…”

“…Their partial pressure was fixed to 49 kPa. DMDS was added to the feed to generate 30 kPa of H 2 S in order to preserve the sulfide state and to prevent deactivation of the catalysts [15]. The partial pressure of hydrogen was kept constant at 5.75 MPa.…”

“…h 1 vs h 5 adsorption [14, 15,23], dissociative vs non dissociative adsorption). In order to get more insight in these phenomena, the adsorption of the phenolic compounds with both catalysts was studied by IR spectroscopy.…”

“…A growing number of experimental studies deals with the HDO of lignocellulosic model compounds in model feeds [10][11][12][13][14][15][16][17][18][19][20][21][22][23] or in coprocessing with petroleum fractions [16,17,24,25]. Phenolic compounds have been proved to be among the most refractory ones to the HDO process [2,7].…”

“…Phenolic compounds have been proved to be among the most refractory ones to the HDO process [2,7]. Hydrodeoxygenation of these molecules proceeds by two pathways: -hydrogenation of the aromatic ring followed by C sp 3-O bond cleavage (HYD pathway); -the direct cleavage of the C sp 2-O bond (DDO pathway) [10][11][12][13][14][15]17]. The Direct DeOxygenation (DDO) reaction pathway is desirable since it limits hydrogen consumption compared to the hydrogenation one.…”