Titanium silicalite (TS-1) without and with extra-framework titanium have been prepared and TiO_2 is 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 TiO_2 does not catalyze H_2O_2 decomposition appreciably compared with TS-1 without extra-framework titanium.The results are very useful in guiding the TS-1 production.
Yaquan WangShuhai WangTeng ZhangJiaxin YeXiao WangDali Wang
The hydrodynamic characteristics of liquid-fluidized magnetically stabilized beds (MSB) with commercial amorphous nickel alloy catalyst (SRNA-4) as solid phase and water as liquid phase in a cold model experimental apparatus of Φ140mm were investigated. The influence of magnetic field intensity on bed structure, pressure drop, minimum fluidization velocity, transition velocity, and liquid holdup were investigated. Mathematical models for minimum fluidization velocity, transition velocity, liquid holdup were established respectively. The operating phase diagrams of liquid-fluidized MSB with SRNA-4 catalyst of two different sizes were obtained.
