Synergetic effect of Te2MoO7 and MoO3 (WO3) oxides in the partial oxidation of propylene

Abstract

This paper presents the synergetic effect of Te2MoO7 and MoO3 (WO3) in the partial oxidation of propylene to acrolein. The study found that the addition of MoO3 (or WO3) to Te2MoO7 greatly promoted the propylene conversion and acrolein yield. As the results of the investigation revealed, the higher catalytic performance could be attributed to the increased acidity, which is beneficial for the adsorption of propylene.Zhejiang Normal University [ZC304008169

Mechanistic Studies of the Oxidation of Cyclohexene to 2-Cyclohexen-1-one over ALD Prepared Titania Supported Vanadia

“…The frequency of this absorption is higher than is typical for carbonate or bicarbonate absorptions, but corresponds well to the position of an absorption of formic acid that was observed in a study of carbon dioxide absorption on titania nanotubes in the presence of adsorbed water. 42 The shift in this absorption by 40 to ∼1740 cm −1 when experiments are conducted in the presence of 18 O 2 at 200 °C (See Figure 8) is consistent with this species containing a carbonyl stretch. 61 Thus, we tentatively assign this absorption to formic acid but cannot rule another carbonylic moiety.…”

“…Oxygen was introduced as part of a flowing mixture of He and O 2 , with the O 2 at a partial pressure of ∼75 Torr. The procedure described for 16 O 2 was also used for 18 O 2 . 18 O 2 was in the form of 10% 18 O 2 in Argon where 18 O 2 was specified as 96% of the total oxygen atoms (Sigma-Aldrich).…”

“…The procedure described for 16 O 2 was also used for 18 O 2 . 18 O 2 was in the form of 10% 18 O 2 in Argon where 18 O 2 was specified as 96% of the total oxygen atoms (Sigma-Aldrich). Background spectra were obtained for the various samples after pretreatment (after step (iii) but before the addition of the reaction mixture).…”

“…3.7. Experiments with 18 O 2 and the Production of Carbon Dioxide (CO 2 ). DRIFT experiments with 18 O 2 provide insights into the source of oxygen incorporated into CO 2 .…”

“…33 Such reoxidation steps have been utilized in chemical processes that involve "looping", where a metal oxide oxidizer is sequentially reduced in the absence of oxygen and then reoxidized with added oxygen. 34 Additionally, experiments with 18 O 2 demonstrate that gas phase oxygen plays a role in the overoxidation of cyclohexene and/or its primary oxidation product(s) to form CO 2 at least at elevated temperatures: ∼250 °C, where it is clearly observed that 18 O is incorporated into the CO 2 overoxidation product. Moreover, the oxidation of cyclohexene epoxide, a proposed intermediate in cyclohexene oxidation, over VO x /TiO 2 has been probed.…”