sc0c03685_si_001.pdf (1.05 MB)
Biophenol-Mediated Solvent-Free Synthesis of Titanium Silicalite‑1 to Improve the Acidity Character of Framework Ti toward Catalysis Application
journal contribution
posted on 2020-08-07, 14:34 authored by Lu Wang, Yan Xu, Guanzhong Zhai, Yanmei Zheng, Jiale Huang, Daohua Sun, Qingbiao LiAlthough
titanium silicalite-1 (TS-1) with enhanced Lewis acidity
can show significant catalytic functionality, the effective and green
synthesis of such a TS-1 zeolite still remains a challenge. In this
work, a biophenol-mediated solvent-free strategy is adopted to synthesize
bio-TS-1 with an improvement of acidity character. Systematic characterizations
are devoted to inspect the structural and acidic properties of the
as-prepared bio-TS-1. Furthermore, density functional theory simulations
are carried out to reveal the underlying mechanism for such an improvement
of acidity. It is found that biophenol serving as a mediating agent
realizes a homogeneous crystallization process for bio-TS-1, which
fundamentally favors titanium substitution of framework sites, especially
those with unique acidity. This improvement of acidity boosts the
intrinsic catalytic reactivity of Ti–OOH species, further increasing
the performances toward propylene epoxidation. The presented strategy
together with mechanistic results clarifies the relationship between
the structure and acidity in TS-1 zeolite and brings forward a promising
approach to develop better TS-1 zeolites by regulating the crystallization
process.