Effect of surface species on activity and selectivity of MoO3/SiO2 catalysts in partial oxidation of methane to formaldehyde

Sol–Gel Synthesis of MoO3/SiO2 Composite for Catalytic Application in Condensation of Anisole with Paraformaldehyde

“…1(A) d) and with the higher MoO 3 loading and the higher calcinations temperature MoO 3 becomes the bulk phase which can be correlated with the catalytic activity of the material. Same trend on the increased loading of MoO 3 was reported in the literature [12], according to these authors, a highly dispersed silicomolybdic species with terminal Mo=O sites exist for low MoO 3 loadings. As the molybdenum content is increased, these sites are transformed into polymolybdate species, forming Mo-O-Mo bridging sites at the expense of Mo=O sites.…”

“…Although, most of the researchers [7,8] use impregnation method but recently some groups report the use of the sol-gel method as an alternative and superior route to the impregnation method for preparing well dispersed MoO 3 /SiO 2 catalysts [9][10][11]. Smith et al [12] has reported the effect of the nature of surface species on the activity and selectivity of MoO 3 /SiO 2 catalysts for the partial oxidation of methane to formaldehyde.…”

Self-catalyzed decomposition of discharge products on the oxygen vacancy sites of MoO3 nanosheets for low-overpotential Li-O2 batteries

“…As an important part in transition metal oxides family, molybdenum oxides, which have been widely used as an oxidation catalysts for organic reactions [36,37], have rarely been demonstrated as catalysts for the Li-O 2 batteries. As can be seen from its crystal structure (Scheme 1), anhydrous MoO 3 is composed of layers of distorted MoO 6 octahedral in an orthorhombic crystal.…”

On the Reactivity of Mo Species for Methane Partial Oxidation on Mo/HMCM-22 Catalysts

“…Several supported oxide catalysts have been employed for this reaction at atmospheric pressure, among them are the supported MoO 3 catalysts, which have been reported to be one of the most active and selective ones for oxygenate production [4][5][6][7][8][9][10][11][12][13]. Silica as a support has been widely used in metal oxide catalysts for methane partial oxidation, and a number of papers have illustrated that silica itself shows discernible activity for formaldehyde formation [14][15][16].…”

“…The most recent papers concerning the catalysts for the title reaction have been focused on the elucidation of the relationship between the structure of the supported metal oxide phase and their role in the reaction mechanism. Smith and Ozkan [7] have examined the partial oxidation of methane to formaldehyde over MoO 3 /SiO 2 , investigated the surface species formed on the support and their effect on reactivity and selectivity [17]. They found that at low Mo loadings, the predominant species was a silicomolybdic species with terminal Mo ¼ O sites.…”