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The gas-phase propylene epoxidation for noble metal system as a green process has confronted a great challenging task in metal utilization and stability. In this work, we realize the enhancement of Au capture efficiency and high-dispersed Au nanoparticles by supports modification and interfacial regulation to construct Au–Fe–TS-1 interface coupling structure. The Au capture efficiency of the optimum catalyst arrived at 69% and it displayed a 7.3% C3H6 conversion with a PO selectivity of 89.9%, giving a H2 efficiency of about 25.7%. Then some typical characterizations systematically elucidate that Fe is not only incorporated into TS-1 framework and captures Au species with high dispersion and stability, but also inhibits the losing of Ti species. Furthermore, Fe-modified catalysts change the property of Au active site and maintain lower apparent activation energy. This report may provide a new strategy to design advanced catalysts for enhancing metal utilization efficiency by the construction of interface coupling structure. [ABSTRACT FROM AUTHOR]

The green direct propylene (C3H6) epoxidation on MoOx is well studied by experimental methods, but detailed molecular reaction mechanism studies using in‐silico experiments method are few. Here, the different oxidation heterogeneous‐homogeneous pathways for MoOx/SiO2 catalyst are calculated, mainly involving Mo=O on di‐oxo tetracoordinate MoOx, allyl peroxy (C3H5OO•), and allyloxy (C3H5O•) radicals. The results show that, for surface reaction mechanism with Mo=O, the barriers of propylene oxide (PO) and acetone generation are too high; in comparison, the byproduct acrolein is more beneficial product with a lower barrier. In heterogeneous‐homogeneous pathways, the desorbed allyl (C3H5•) from the surface can easily combine with O2 to synthesize C3H5OO• radical, and in the partial oxidation of propylene with C3H5OO• as an oxidant, PO is more beneficial with a low barrier compared to byproducts such as propanal, acetone, acetaldehyde, etc. These indicate that (a) gas‐phase free radical reactions have important effects on PO generation, in which C3H5OO• is the main active species; (b) on MoOx surface, Mo=O is difficult to be used as the active O species for PO production. Further research is needed on other active sites such as Mo‐O‐Mo or defective sites. [ABSTRACT FROM AUTHOR]

We have successfully constructed electron‐rich Bi and Mo species with a highly degree of dispersion and hierarchical pore texture by introducing Cu/SiO2 as a bi‐functional modifier for MoO3‐Bi2SiO5/SiO2. Characterization techniques suggest the Bi species was modified by Cu with a Bi‐O−Cu coordination structure, and copper species became a capture site for Mo species that improved the dispersity and interface bonding strength of Mo and regulated electron structure of Bi and Mo species, synchronously. Additionally, the hierarchical pore was constructed by compositing Cu/SiO2 with Bi2SiO5/SiO2 support. [ABSTRACT FROM AUTHOR]

The gas-phase propylene epoxidation for noble metal system as a green process has confronted a great challenging task in metal utilization and stability. In this work, we realize the enhancement of Au capture efficiency and high-dispersed Au nanoparticles by supports modification and interfacial regulation to construct Au–Fe–TS-1 interface coupling structure. The Au capture efficiency of the optimum catalyst arrived at 69% and it displayed a 7.3% C3H6 conversion with a PO selectivity of 89.9%, giving a H2 efficiency of about 25.7%. Then some typical characterizations systematically elucidate that Fe is not only incorporated into TS-1 framework and captures Au species with high dispersion and stability, but also inhibits the losing of Ti species. Furthermore, Fe-modified catalysts change the property of Au active site and maintain lower apparent activation energy. This report may provide a new strategy to design advanced catalysts for enhancing metal utilization efficiency by the construction of interface coupling structure. [ABSTRACT FROM AUTHOR]

We have successfully constructed electron‐rich Bi and Mo species with a highly degree of dispersion and hierarchical pore texture by introducing Cu/SiO2 as a bi‐functional modifier for MoO3‐Bi2SiO5/SiO2. Characterization techniques suggest the Bi species was modified by Cu with a Bi‐O−Cu coordination structure, and copper species became a capture site for Mo species that improved the dispersity and interface bonding strength of Mo and regulated electron structure of Bi and Mo species, synchronously. Additionally, the hierarchical pore was constructed by compositing Cu/SiO2 with Bi2SiO5/SiO2 support. [ABSTRACT FROM AUTHOR]