Modification of small-crystal titanium silicalite-1 with organic bases: Recrystallization and catalytic properties in the hydroxylation of phenol

Effect of triethylamine treatment of titanium silicalite-1 on cyclohexanone ammoximation in a continuous system

“…S1). This phenomenon is the same as the treatment on TS-1 by other organic amine reported in the literature [39,41,45]. All the TS-1 samples show the same morphology of ellipsoids and crystal sizes of 200 nm in the SEM images (see Fig.…”

“…The higher the TEA concentration, the higher the treatment temperature and the longer the treatment time are, the lower the relative crystallinity of TS-1 is. It has been reported that the silica atoms in the zeolite could be dissolved into the solution in the base treatment and the dissolved silica might be recrystallized in the presence of templates, such as TPAOH [34,39,41]. The treatment of TS-1 with TEA can also cause the dissolution of silica, but the dissolved silica is difficult to recrystallize because TEA cannot structure-direct the synthesis of the MFI topology, Table 1.…”

“…Tsai et al [40] treated TS-1 in turn with TPAOH and NaOH to generate cavities and mesopores and thus the catalytic performance in phenol hydroxylation was improved. Guo and coworkers [41] treated TS-1 with ethylamine, diethylamine, tetramethyl ammonium hydroxide, TPAOH and tetrabutyl ammonium hydroxide to create hollow cavities and the TS-1 samples treated by TPAOH exhibited the highest catalytic activities in the phenol hydroxylation. The above reports indicate that TPAOH is an effective agent to create hollow cavities in TS-1.…”

Effect of triethylamine treatment of titanium silicalite-1 on propylene epoxidation

“…Other groups [19,[27][28] have also reported that TPAOH is an effective agent to create hollow cavities in TS-1. However, TPAOH is very expensive and cannot be recycled.…”

“…The direct epoxidation of propylene to PO over TS-1 using hydrogen peroxide as the oxidant is regarded as an important development trend of PO green production for its mild reaction conditions, high catalytic activity and high atom economy [12][13][14][15][16][17][18]. However, the application of TS-1 as catalyst suffers from diffusional limitation on the reaction due to the size of the zeolite channels (0.56 nm  0.53 nm) [19]. In order to overcome this problem, several approaches have been developed to introduce mesopores and macropores into zeolite.…”