Effect of Extra-Framework Titanium in TS-1 on the Ammoximation of Cyclohexanone

Titanium silicalite (TS-1) without and with extra-framework titanium have been prepared and TiO2is also prepared under the same conditions.All the samples are characterized with XRD,FT-IR,and UV–Vis.The effects of extra-framework titanium in TS-1 on the ammoximation of cyclohexanone have been studied in a continuous slurry reactor.The characterization results reveal that the extra-framework titanium exists as anatase.The catalytic evaluation results show that the anatase has a positive effect on the ammoximation of cyclohexanone by extending the catalytic life because it also exhibits some activity,while the conversion of cyclohexanone and the selectivity to cyclohexanone oxime are not influenced.The anatase TiO2does not catalyze H2O2decomposition appreciably compared with TS-1 without extra-framework titanium.The results are very useful in guiding the TS-1 production.