Tao Guo, Baorong Wang*, Chenlong Xue, Xiaomeng Liu, Chunhua Lin, Xianqing Xie, Yibin Luo, Weilin Liao* and Xingtian Shu,
{"title":"原位调整硅酸钛-1(TS-1)的晶体缺陷以提高 1-丁烯环氧化性能","authors":"Tao Guo, Baorong Wang*, Chenlong Xue, Xiaomeng Liu, Chunhua Lin, Xianqing Xie, Yibin Luo, Weilin Liao* and Xingtian Shu, ","doi":"10.1021/acs.iecr.4c01380","DOIUrl":null,"url":null,"abstract":"<p >The crystalline defects are vitally important for the catalytic activity and stability of zeotype materials; however, the influences of which on the catalytic performance of TS-1 should further be studied. Herein, a modified hydrothermal synthesis process was developed to in situ tailor the framework defects of TS-1, and the physicochemical properties and catalytic performance were studied in detail. Generally, the <i>n</i><sub>H<sub>2</sub>O</sub>/<i>n</i><sub>SiO<sub>2</sub></sub> (5–20) of the precursor mixture was in situ tuned via distillation through the crystallization under 90–110 °C, and TS-1 with decreased framework defects can be directly synthesized during the following crystallization under 170 °C. When the <i>n</i><sub>H<sub>2</sub>O</sub>/<i>n</i><sub>SiO<sub>2</sub></sub> declined, the crystal size decreased; however, more intracrystalline mesopores (3.0–5.3 nm) can be introduced, the mesopore volume increased from 0.051 to 0.083 cm<sup>3</sup>/g. More importantly, the ratio of silicon species in Q4 (Si(OSi)<sub>4</sub>) to Q3 [Si(OSi)<sub>3</sub>(OH)] units increased from 29.9 to 55.0, and the hydroxyl groups in the nest or neighboring environments decreased more significantly than the surface silanol. Nevertheless, the titanium coordination states remained unchanged. Owing to the decreased framework defects, the weak acid sites declined from 191.5 to 160.5 μmol NH<sub>3</sub>/g, the epoxide selectivity in butene epoxidation reaction increased from 97.4 to 98.1%, while the H<sub>2</sub>O<sub>2</sub> efficiency was enhanced from 96.7 to 98.6%. More importantly, the catalytic stability of TS-1 was also improved.</p>","PeriodicalId":39,"journal":{"name":"Industrial & Engineering Chemistry Research","volume":null,"pages":null},"PeriodicalIF":3.8000,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"In Situ Tailoring the Crystalline Defects of Titanium Silicalite-1 (TS-1) to Improve the 1-Butene Epoxidation Performance\",\"authors\":\"Tao Guo, Baorong Wang*, Chenlong Xue, Xiaomeng Liu, Chunhua Lin, Xianqing Xie, Yibin Luo, Weilin Liao* and Xingtian Shu, \",\"doi\":\"10.1021/acs.iecr.4c01380\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p >The crystalline defects are vitally important for the catalytic activity and stability of zeotype materials; however, the influences of which on the catalytic performance of TS-1 should further be studied. Herein, a modified hydrothermal synthesis process was developed to in situ tailor the framework defects of TS-1, and the physicochemical properties and catalytic performance were studied in detail. Generally, the <i>n</i><sub>H<sub>2</sub>O</sub>/<i>n</i><sub>SiO<sub>2</sub></sub> (5–20) of the precursor mixture was in situ tuned via distillation through the crystallization under 90–110 °C, and TS-1 with decreased framework defects can be directly synthesized during the following crystallization under 170 °C. When the <i>n</i><sub>H<sub>2</sub>O</sub>/<i>n</i><sub>SiO<sub>2</sub></sub> declined, the crystal size decreased; however, more intracrystalline mesopores (3.0–5.3 nm) can be introduced, the mesopore volume increased from 0.051 to 0.083 cm<sup>3</sup>/g. More importantly, the ratio of silicon species in Q4 (Si(OSi)<sub>4</sub>) to Q3 [Si(OSi)<sub>3</sub>(OH)] units increased from 29.9 to 55.0, and the hydroxyl groups in the nest or neighboring environments decreased more significantly than the surface silanol. Nevertheless, the titanium coordination states remained unchanged. Owing to the decreased framework defects, the weak acid sites declined from 191.5 to 160.5 μmol NH<sub>3</sub>/g, the epoxide selectivity in butene epoxidation reaction increased from 97.4 to 98.1%, while the H<sub>2</sub>O<sub>2</sub> efficiency was enhanced from 96.7 to 98.6%. 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In Situ Tailoring the Crystalline Defects of Titanium Silicalite-1 (TS-1) to Improve the 1-Butene Epoxidation Performance
The crystalline defects are vitally important for the catalytic activity and stability of zeotype materials; however, the influences of which on the catalytic performance of TS-1 should further be studied. Herein, a modified hydrothermal synthesis process was developed to in situ tailor the framework defects of TS-1, and the physicochemical properties and catalytic performance were studied in detail. Generally, the nH2O/nSiO2 (5–20) of the precursor mixture was in situ tuned via distillation through the crystallization under 90–110 °C, and TS-1 with decreased framework defects can be directly synthesized during the following crystallization under 170 °C. When the nH2O/nSiO2 declined, the crystal size decreased; however, more intracrystalline mesopores (3.0–5.3 nm) can be introduced, the mesopore volume increased from 0.051 to 0.083 cm3/g. More importantly, the ratio of silicon species in Q4 (Si(OSi)4) to Q3 [Si(OSi)3(OH)] units increased from 29.9 to 55.0, and the hydroxyl groups in the nest or neighboring environments decreased more significantly than the surface silanol. Nevertheless, the titanium coordination states remained unchanged. Owing to the decreased framework defects, the weak acid sites declined from 191.5 to 160.5 μmol NH3/g, the epoxide selectivity in butene epoxidation reaction increased from 97.4 to 98.1%, while the H2O2 efficiency was enhanced from 96.7 to 98.6%. More importantly, the catalytic stability of TS-1 was also improved.
期刊介绍:
ndustrial & Engineering Chemistry, with variations in title and format, has been published since 1909 by the American Chemical Society. Industrial & Engineering Chemistry Research is a weekly publication that reports industrial and academic research in the broad fields of applied chemistry and chemical engineering with special focus on fundamentals, processes, and products.