Abstract：Ammoximation of benzaldehyde (BA) catalyzed by titanosilicate provides an eco-friendly route for synthesizing benzaldehyde oxime (BAO). However, BA is so active that several side reactions would happen during ammoximation, such as self polymerization and oxidation with H2O2, resulting in low BAO selectivity. Thus, the reaction network and the catalytic performance under different Ti species were evaluated for the ammoximation of BA. It is identified that the four-coordinated framework Ti species are the active centers in the ammoximation reaction. Hollow titanium silicalite (HTS) showed more excellent catalytic performance than TS-1, owing to better properties of diffusion. The effects of various parameters, such as catalyst amount, NH3/BA and H2O2/BA molar ratios, the way of feeding H2O2 and reaction temperature, on the catalytic performance of HTS were investigated in detail. Under the optimized reaction conditions, BA conversion and BAO selectivity are 99.9% and 95.8% respectively. Moreover, the repeated experiment results showed the good catalytic stability of HTS.
Yang Yongjia,Xia Changjiu,Lin Min et al. Ammoximation of Benzaldehyde Catalyzed by Hollow Titanium Silicalite Zeolite[J]. 化学反应工程与工艺, 2018, 34(5): 440-447.
