Fabrication Of Oriented TS-1Films And Application In Plated Micro Reactor For Catalyzing The Reaction Of Cyclohexanone Ammoximation

Titanium Silicalite-1(TS-1) molecular sieve possesses an outstandingshape-selective catalysis in a series of organic catalytic-oxidation reactions with H2O2as oxidant due to its unique pore structure, and TS-1molecular sieve films supportedon substrate have potential applications in the oxidation reactions. In this paper,b-oriented TS-1molecular sieve films were fabricated by stepwise steaming-assistedcrystallization, hydrothermal synthesis and secondary growth, respectively. Moreover,a narrow-sized plated micro reactor was constructed and used to evaluate the reactionof cyclohexanone ammoximation. The main researchs and results are as follows:1. TS-1molecular sieve films grew on the surface of silicon wafers bysteaming-assisted crystallization, and the effects of the volume ratios of H2O inautoclave and crystallization methods on TS-1films were also investigated. Theresults showed that b-oriented TS-1film could be prepared over the silicon wafer bystepwise steaming-assisted crystallization, and such a method avoided the formationof the dried gel over the Si wafer before crystallization, and allowed the limitedconsumption of template required for growing TS-1crystals. In contrast to one-stepsteaming-assisted crystallization, the stepwise crystallization reduced crystallizationtime for the formation of the oriented TS-1film. In addition, the increased volumeratio of water was in favor for the preparation of the b-oriented TS-1film.2. The surface of glasses was modified with TS-1precursors by sol-gel method,and b-oriented TS-1monolayer grew on the modified glass by hydrothermal synthesis.The effects of immersion time, rotation of autoclave and crystallization on TS-1filmswere investigated. The results showed that the oriented TS-1monolayer could beprepared with the immersion time of12h. A b-oriented TS-1monolayer could befabricated on the glass with the rotation speed of10rad/min and the crystallizationtime of24h.3. TS-1seed layers with the different sizes of TS-1crystals were prepared onPAM-modified glasses by evaporation-deposition method. The effects ofcrystallization time of secondary growth on TS-1films were also investigated. Theresult showed that the PAM-modified glasses were in favor for the oriented alignmentof TS-1crystals. The oriented TS-1film could be formed on the glass while the crystallization time of secondary growth was12h, and non-b oriented TS-1filmthickness increased with the increasing crystallization time.4. The narrow-sized micro reactor was constructed to evaluate the catalyticperformance of oriented and random TS-1films in the reaction of cyclohexanoneammoximation. The effects of different reaction conditions on the cyclohexanoneconversion and the oxime selectivity and the catalyst lifetime of the oriented TS-1films were investigated. In the reaction of cyclohexanone ammoximation, thecyclohexanone conversion and the oxime selectivity of the oriented TS-1films were0.96and0.98, but the conversion and the selectivity of random ones were merely0.81and0.82; the optimized condition of reaction was WHSV of5h-1or10h-1, theamount of TS-1of0.16g, reaction temperature of343K, and the cyclohexanoneconversion and the oxime selectivity were0.97and0.98, respectively, meanwhile, thelifetimes of the reaction were144h or94h.