Premium
Synthesis of Hierarchical Titanium‐Rich Titanium Silicalite‐1 Zeolites and the Highly Efficient Catalytic Performance for Hydroxylation of Phenol
Author(s) -
Han Zongzhuang,
Shen Yun,
Qin Xiaofei,
Wang Fumin,
Zhang Xubin,
Wang Gang,
Li. Haichao
Publication year - 2019
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.201803864
Subject(s) - titanium , phenol , hydroxylation , catalysis , tetraethyl orthosilicate , ammonium hydroxide , fourier transform infrared spectroscopy , inorganic chemistry , ammonium carbonate , zeolite , chemistry , nuclear chemistry , materials science , chemical engineering , organic chemistry , engineering , enzyme
Improving the framework titanium (Ti) of titanium silicalite‐1 (TS‐1) zeolites and creating inter‐crystalline mesoporosity are two ways to enhance the catalytic properties of TS‐1 for hydroxylation of phenol. Most researches only used one of the ways. In this study, we successfully synthesized of hierarchical Titanium‐Rich (Ti‐rich) TS‐1. Ti‐rich TS‐1 was synthesized in the presence of ammonium carbonate ((NH 4 ) 2 CO 3 ). The framework Ti content of TS‐1 zeolites synthesized by different content of (NH 4 ) 2 CO 3 was studied by X‐ray fluorescence (XRF), Fourier transform infrared spectra (FTIR) and ultraviolet visible spectra, the framework Ti content was significantly increased by using (NH 4 ) 2 CO 3 as crystallization‐mediating agent. The synthesized samples were evaluated in hydroxylation of phenol. When the molar ratio of ammonium carbonate and tetraethyl orthosilicate in the synthesis gel was 0.2, the molar ratio of Si/Ti reached 34.43 and the Ti‐rich TS‐1 shows the optimum catalytic activity in hydroxylation of phenol. The post‐modification with aqueous solution of tetrapropylammonium hydroxide (TPAOH) was used to further improve the diffusion property. Compared with the parent TS‐1, the secondary pore volume was all increased. The developed hierarchical Ti‐rich TS‐1 zeolites were also assessed in hydroxylation of phenol. It was confirmed that hierarchical Ti‐rich titanium silicalite‐1 zeolites can improve the catalytic activity in phenol conversion considerably.