Open AccessEffect of oxomolybdate species dispersion on direct methanol oxidation to dimethoxymethane over MoO x /TiO 2 catalysts
Author(s) -
Faye Jérémy,
Capron Mickaël,
Takahashi Atsushi,
Paul Sébastien,
Katryniok Benjamin,
Fujitani Tadahiro,
Dumeignil Franck
Publication year - 2015
Publication title -
energy science and engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.638
H-Index - 29
ISSN - 2050-0505
DOI - 10.1002/ese3.53
Subject(s) - dimethoxymethane , catalysis , methanol , physisorption , redox , chemistry , inorganic chemistry , molybdenum , incipient wetness impregnation , formaldehyde , dispersion (optics) , organic chemistry , selectivity , optics , physics
Abstract The one‐step selective oxidation of methanol to dimethoxymethane (DMM) was demonstrated over titania‐supported molybdenum oxide catalysts, containing different amounts of molybdenum and prepared using two different impregnation techniques, namely wet impregnation and incipient wetness impregnation. The corresponding catalysts exhibited both acidic and redox properties, which are necessary for the oxidation of methanol to formaldehyde with subsequent condensation of the latter with excess methanol to finally yield DMM. The formation of well‐dispersed polyoxomolybdate species on the catalyst surface was evidenced using IR‐Raman, X‐ray diffraction, and nitrogen physisorption. Varying the amount of these polyoxomolydate species was associated with a modulation of the acidic and redox properties, as shown by NH 3 ‐TPD and H 2 ‐TPR. With respect to the catalytic performances, the best balance between acid and redox properties was observed over the samples containing 8 wt.% Mo, which corresponds to a theoretical MoO x species coverage close to a monolayer.