Engineering a Coordinatively Unsaturated Au–O–Ti3+ Structure Toward Unprecedented H2 Efficiency for Low-Temperature Propene Epoxidation with H2 and O2

Low Concentration Template Preparation of Microsized Au/TS-1 as an Efficient Catalyst for Gas-Phase Propylene Epoxidation with H2 and O2

“…As shown in Figure 3b, all the samples exhibit two NH 3 desorption peaks at 166 and 334 °C, which are ascribed to weak and medium acid centers. 14,40,44 The amount of weak and medium acid sites slightly increases from TS-1-S to TS-1-L. It should be noted that the intensity of the medium acid sites is weak, and no strong acid site can be observed.…”

“…The opposite result indicates that the electronic structure and local environment of the active sites may play important roles in this study. The coordinatively unsaturated Ti 3+ enhances the electron transfer between Au–Ti to form the Au–O–Ti 3+ active site, which promotes oxygen activation and the generation of Ti-OOH reactive species . Meanwhile, the higher Au binding energy would facilitate the formation of hydroperoxide species by enhancing the Au–H interaction, , and low Ti binding energy favors propylene activation .…”

Constructing Highly Efficient Ti Sites of TS-1 for Alkene Epoxidation

“…Song et al synthesized TS-1 with different contents of hexacoordinated Ti species by regulating the content of silanols and Bu 3 NH + in post-treated S-1 seeds as shown in Figure 5a. 76 These hexa-coordinated Ti species are coordinatively unsaturated Ti 3+ sites which could be proved by the X-ray photoelectron spectroscopy (XPS) and UV−vis spectra (Figure 5b,c). The unique unsaturated Ti 3+ sites could promote the electron transfer between the Ti 3+ sites and loading Au nanoparticles, thus enhancing the O 2 adsorption which is demonstrated by the Mulliken charge distribution.…”

“…Song et al synthesized TS-1 with different contents of hexa-coordinated Ti species by regulating the content of silanols and Bu 3 NH + in post-treated S-1 seeds as shown in Figure a . These hexa-coordinated Ti species are coordinatively unsaturated Ti 3+ sites which could be proved by the X-ray photoelectron spectroscopy (XPS) and UV–vis spectra (Figure b,c).…”

“…(d) Schematic diagram of operando UV–vis equipment and the operando UV–vis spectra of different Au/TS-1 catalysts during direct propene epoxidation with H 2 and O 2 . Reproduced with permission from ref . Copyright 2023 Elsevier.…”