TY - JOUR
T1 - Controllable construction of highly active Ti species in TS-1 zeotype by organic base treatment
AU - Li, Shiqing
AU - Tuo, Jie
AU - Peng, Rusi
AU - Gong, Xianchen
AU - Ma, Ying
AU - Xu, Hao
AU - Wu, Peng
N1 - Publisher Copyright:
© 2025 The Royal Society of Chemistry.
PY - 2024/12/19
Y1 - 2024/12/19
N2 - Regulating the microenvironment of Ti active centers in titanosilicates is of great significance in both theoretical research and practical application of titanosilicate/H2O2 systems. Herein, a novel six-coordinated Ti species containing an organic amine ligand, Ti(OSi)2(OH)2(H2O)TPA, was constructed in the TS-1 zeotype in the process of dissolution and recrystallization by hydrothermal post-treatment with tetrapropylammonium hydroxide and ammonium chloride. The newly formed hexa-coordinated Ti species promoted the activation of H2O2 significantly, responsible for the superior catalytic activity in 1-hexene epoxidation with a conversion of 35.5% compared with the untreated TS-1 (18.0%). After removal of organics by calcination, Ti(OSi)2(OH)2(H2O)TPA was transformed into Ti(OSi)2(OH)2(H2O)2 sites, which also exhibited higher epoxidation activity compared to the original framework Ti(OSi)4 sites. In addition, the acid sites of Si-OH in TS-1 zeotype were quenched by the basic amine molecules, which effectively inhibited the occurrence of side reactions such as epoxide ring opening, leading to a high epoxide selectivity of 98.6%. With the construction of highly active Ti(OSi)2(OH)2(H2O)TPA sites and without further calcination process, the obtained catalyst (denoted as TS-PN-am) exhibited not only excellent catalytic capacity but also application potential in continuous liquid-phase epoxidation.
AB - Regulating the microenvironment of Ti active centers in titanosilicates is of great significance in both theoretical research and practical application of titanosilicate/H2O2 systems. Herein, a novel six-coordinated Ti species containing an organic amine ligand, Ti(OSi)2(OH)2(H2O)TPA, was constructed in the TS-1 zeotype in the process of dissolution and recrystallization by hydrothermal post-treatment with tetrapropylammonium hydroxide and ammonium chloride. The newly formed hexa-coordinated Ti species promoted the activation of H2O2 significantly, responsible for the superior catalytic activity in 1-hexene epoxidation with a conversion of 35.5% compared with the untreated TS-1 (18.0%). After removal of organics by calcination, Ti(OSi)2(OH)2(H2O)TPA was transformed into Ti(OSi)2(OH)2(H2O)2 sites, which also exhibited higher epoxidation activity compared to the original framework Ti(OSi)4 sites. In addition, the acid sites of Si-OH in TS-1 zeotype were quenched by the basic amine molecules, which effectively inhibited the occurrence of side reactions such as epoxide ring opening, leading to a high epoxide selectivity of 98.6%. With the construction of highly active Ti(OSi)2(OH)2(H2O)TPA sites and without further calcination process, the obtained catalyst (denoted as TS-PN-am) exhibited not only excellent catalytic capacity but also application potential in continuous liquid-phase epoxidation.
UR - https://www.scopus.com/pages/publications/85212766073
U2 - 10.1039/d4cy01313a
DO - 10.1039/d4cy01313a
M3 - 文章
AN - SCOPUS:85212766073
SN - 2044-4753
VL - 15
SP - 722
EP - 733
JO - Catalysis Science and Technology
JF - Catalysis Science and Technology
IS - 3
ER -