Solar Photocatalytic Oxidation of Methane to Methanol with Water over RuO_x/ZnO/CeO₂ Nanorods

Abstract

Due to the high stability and chemical inertia of methane, CH 4 , its selective conversion into value-added organic chemicals under mild conditions has been widely regarded as an important reaction for the chemical industry. Here, we develop a RuO x decorated ZnO/CeO 2 photocatalyst for the highly efficient and selective transformation of CH 4 into CH 3 OH under simulated solar light irradiation. The CH 3 OH generation rate over the optimized RuO x /ZnO/CeO 2 composite is 133.54 μmol g −1 h −1 with 97.7% selectivity, which is 20 times higher than that of a ZnO/CeO 2 reference system (6.56 μmol g −1 h −1 ) which only exhibits moderate selectivity (40.5%). We find that the significant boost to the photocatalytic performance is attributable to accelerated interfacial charge separation and a beneficial rise in free hydroxyl radical generation from water oxidation in the presence of RuO x clusters.

Understanding (photo)electrocatalysis for the conversion of methane to valuable chemicals through partial oxidation processes

“…4a). 27–31 The opposite outcome was also reported, i.e. , mobile ˙OH stimulates the formation of C 2 H 6 , whereas the reaction of surface-bound ˙OH with CH 3 ˙ selectively produces methanol (Fig.…”

“…Reproduced with permission. 31 Copyright 2022, American Chemical Society. (b) Change of the reaction pathway for CH 4 oxidation before and after the surface fluorination of WO 3 .…”

Construction of a Bi2MoO6/CoOx/Au system with a dual-channel charge transfer path for enhanced tetracycline degradation

“…41,42 Fortunately, transition metal oxides have been considered as one of the best candidates for effectively extracting holes and constructing hole transport channels. [43][44][45][46] Among them, CoO x has attracted the interest of many researchers in practical application on account of its high efficiency, affordable cost, and earth abundance. Li et al demonstrated that the CoO x cocatalyst could effectively capture holes in a few picoseconds and dramatically prolong the lifetime of photogenerated holes.…”

Synergistic photocatalytic CH4 conversion to C1 liquid products using Fe oxide species-modified g-C3N4

“…28 This not only greatly increases the number of active centers, but also results in improved photocatalytic performance via synergistic effects. 31,32 As compared to oxygen and N 2 O, H 2 O 2 oxidants are much more effective to catalyze CH 4 under mild conditions via generating hydroperoxy intermediate products. 10 However, for H 2 O 2 based CH 4 conversion, the effective utilization of H 2 O 2 to reduce cost is the main bottleneck.…”

“…28 This not only greatly increases the number of active centers, but also results in improved photocatalytic performance via synergistic effects. 31,32…”