Beneficial Effect of W Incorporation in Supported Mo‐based Catalysts for the HDO of m‐Cresol
Résumé
The hydrodeoxygenation (HDO) of m-cresol was investigated at
340°C under 30 bar as total pressure over molybdenum oxidebased
catalysts. 10 wt.% Mo were first deposited on various
supports (ZrO2, TiO2, Al2O3 and COK12). The use of oxophilic
ZrO2 and TiO2 supports allowed to obtain the highest HDO
catalytic performances. This result could be in link with the
reducibility of Mo, which was found to be dependent on the
support nature. Several catalysts containing both W and Mo in
oxide phase supported on ZrO2 were then prepared using
various heteropolyacids as precursors (H4SiMoxW12-xO40 with x=
0, 3, 6, 9 and 12). A synergy was observed between Mo and W
and the best catalytic performance was obtained for SiMo9W3/
ZrO2. More importantly, the presence of W improved the
reducibility of Mo6+ to Mo5+ species, which quantity was
correlated to catalytic activity suggesting that Mo5+ could be
the active phase in HDO