Understanding the water-involved mechanism on metal oxide surface and the dynamic interaction of water with active sites is crucial in solving water poisoning in catalytic reactions. Herein, this work solves this problem by designing the water-promoted function of metal oxides in the ethanol oxidation reaction. In situ multimodal spectroscopies unveil that the competitive adsorption of water-dissociated *OH species with O 2 at Sn active sites results in water poisoning and the sluggish proton transfer in CoO-SnO 2 imparts water-resistant effect. Carbon material as electron donor and proton transport channel optimizes the Co active sites and expedites the reverse hydrogen spillover from CoO to SnO 2 . The water-promoted function arises from spillover protons facilitating O 2 activation on the SnO 2 surface, leading to crucial *OOH intermediate formation for catalyzing C-H and C-C cleavage. Consequently, the tailored CoO-C-SnO 2 showcases a remarkable 60-fold enhancement in ethanol oxidation reaction compared to bare SnO 2 under high-humidity conditions.
Supported PdAu bimetallic nanoparticles have been developed for the direct synthesis of H 2 O 2 (DSHP). However, to date, the dilute H 2 streams necessary to avoid potential risks of explosion limits the attainable product concentrations of H 2 O 2 . Here, a series of silicon-modified Al 2 O 3 (Si x Al) were synthesized for loading PdAu bimetallic nanoparticles . The H 2 consumption turnover frequency (TOF) and H 2 O 2 formation TOF show a volcano trend with the silica content, where PdAu/Si 5.6 Al exhibits the best H 2 consumption TOF and H 2 O 2 formation TOF (11259.3 and 1995.2 h −1 ). Silica on the surface of Al 2 O 3 is identified as Brønsted (B) acid site. The increase of B acid sites density accelerates the H 2 conversion into H atoms, thereby boosting H 2 O 2 formation process. The adsorption and dissociation of H 2 into atomic H at B acid sites would spill across the support to PdAu nanoparticles reversely. The reversed hydrogen spillover effect induced by B acid site accounts for enhanced H 2 conversion and H 2 O 2 productivity for PdAu/Si x Al.
危险品化学品经营许可证（带存储）