What is the effect of Sn and Mo oxides on gold catalysts for selective oxidation of benzyl alcohol?

Abstract

A series of SnOx and MoOx promoted gold nanoparticle catalysts were used for the aerobic oxidation of benzyl alcohol.

Importance of Size and Contact Structure of Gold Nanoparticles for the Genesis of Unique Catalytic Processes

“…Deposition of reducible MO x onto inert supports is one strategy to obtain highly dispersed small reducible MO x particles. Au NPs deposited on reducible MO x /inert supports, such as Au/Ce–SiO 2 , Au/SnO x –SiO 2 , and Au/CeO 2 - g -C 3 N 4 , have been reported to work as catalysts for oxidation reactions. These catalytic activities are a result of the interactions between Au and reducible MO x .…”

“…In the case of Au/SnO x −mesoporous SiO 2 , the MTY was 15,348 h −1 for benzyl alcohol oxidation under solvent-free and base-free conditions (Table 14). 390 The high activity was explained by electron transfer between SnO x and Au and lattice distortion of Au, leading to more low-coordinate Au NPs. On the other hand, no lattice distortion was observed for Au/MoO x − mesoporous SiO 2 , resulting in activity similar to that of Au/ mesoporous SiO 2 .…”

Compatibility between Activity and Selectivity in Catalytic Oxidation of Benzyl Alcohol with Au–Pd Nanoparticles through Redox Switching of SnOx

“…The size effect of the NP catalyst and the distribution of metal elements play important roles in their catalytic performance. 23,36 The representative STEM-HAADF images and the corresponding EDS spectral maps of catalyst AP-ox indicated the presence of well-dispersed Au and Pd on the MCF support. Moreover, the energy dispersive line scan across NPs revealed the consistent dispersion of these two elements, indicating the formation of Au-Pd nano-alloys, which is in agreement with the UV-vis results.…”

“…In summary, tin is a potential promoter for in situ reduction of surface PdO species because it is more oxophilic and can also effectively enhance the benzaldehyde selectivity on the Au NP catalyst by regulating surface affinity. 23 In this paper, we report on the preparation of Au−Pd bimetallic NP catalyst modified with Sn/SnO x . First, the mesostructured cellular foam silica (MCF)-supported Au−Pd NP catalyst (AP-ox) was prepared by a one pot method.…”

“…The promoted catalyst exhibited high H 2 O 2 selectivity attributable to the presence of the SnO x surface layer, which prevented further hydrogenation and decomposition of H 2 O 2 . In our previous work, we found that applying the SnO x -promoted Au nanoparticle (NP) catalyst for benzyl alcohol oxidation can effectively reduce the disproportionation reaction, achieving high benzaldehyde selectivity. In summary, tin is a potential promoter for in situ reduction of surface PdO species because it is more oxophilic and can also effectively enhance the benzaldehyde selectivity on the Au NP catalyst by regulating surface affinity …”