The construction and determination of highly active Ti sites comprise one of the most significant challenges in the rational design and synthesis of Ti-containing porous catalysts. The pathway to efficiently build highly catalytically active titanium species remains to be proposed in spite of deliberate post treatments or ambiguous batch composition adjustments. In this study, we developed a bottom–up strategy to construct a TS-1 catalyst with highly active hydrogen-bonded Ti species via subcrystal aggregation crystallization. The microstructure of the hydrogen-bonded Ti species was verified by vacuum FT-IR and ¹H MAS SSNMR spectroscopies. Noteworthy features of the hydrogen-bonded Ti species were also revealed, including a pentahedral coordination state and Brønsted acidity, as identified by the UV–Raman, XPS, XAFS, and FT-IR spectra of adsorbed pyridine. Significantly, the hydrogen-bonded Ti species exhibits extraordinary activity in allyl chloride epoxidation (nearly 70% higher than that of traditional Ti species). This study provides a new approach to building highly active Ti sites, which may provide new insights into the design and synthesis of high-performance titanosilicate catalysts.

中文翻译：

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通过亚晶聚集合成 TS-1：构建用于烯烃环氧化的高活性氢键钛物种

高活性 Ti 位点的构建和确定是含 Ti 多孔催化剂的合理设计和合成中最重大的挑战之一。尽管经过深思熟虑的后处理或模糊的批次组成调整，但仍有待提出有效构建高催化活性钛物种的途径。在这项研究中，我们开发了一种自下而上的策略，通过亚晶聚集结晶构建具有高活性氢键 Ti 物质的 TS-1 催化剂。^{通过真空 FT-IR 和1}验证了氢键合 Ti 物种的微观结构H MAS SSNMR 光谱。还揭示了氢键合 Ti 物种的值得注意的特征，包括五面体配位态和 Brønsted 酸度，如吸附吡啶的 UV-Raman、XPS、XAFS 和 FT-IR 光谱所鉴定的那样。值得注意的是，氢键合钛物种在烯丙基氯环氧化反应中表现出非凡的活性（比传统钛物种高出近 70%）。该研究为构建高活性钛位点提供了一种新方法，可能为高性能钛硅酸盐催化剂的设计和合成提供新的思路。