Synthesis And Catalytic Performance Study Of Zeolite Molecular Sieve Silicoaluminophosphate SAPO-11 Supported MoO₃ Catalysts

Zeolites,as the most important nanoporous materials,have complex micro/mesoporous structures which are widely used in gas separation,ion exchange and catalysis.Zeolites are usually hydrothermally synthesized using organic templating methods?OSDAs?;however,the use of expensive OSDAs produces large amounts of sewage and nitrogen oxide?NOx?harmful gases,so this method is often more expensive and environmentally unfriendly.These shortcomings undoubtedly hinder the practical application of OSDAs.The best way to solve these problems is to achieve non-organic templating or did not use organic template synthesis of zeolites,thereby avoiding the use of expensive OSDAs.In this paper,mesoporous silicoaluminophosphate SAPO-11 was synthesized by using green and low-cost sucrose as template.The sucrose is introduced into the SAPO-11 crystal structure to form secondary mesoporous.Meanwhile,MoO₃ supported mesoporous Mo^VI/SAPO-11 samples with different crystal phases were synthesized.Then we applied the pre-prepared catalyst in the following two reactions to study catalytic performance:?1?The synthesized catalyst was first used in the oxidative desulfurization?ODS?reaction.The experiment showed that the?-MoO₃/SAPO-11-3.6?content of molybdenum:3.6%by weight?catalyst of orthorhombic has excellent desulfurization performance,using 10 mL model oil?500ppm?.The reaction conversion rate reached 99.9%under the optimal conditions of the molar ratio of oxygen:sulfur atom was10:1?oxidant H₂O₂?and the reaction temperature was 60°C.Interestingly,the Mo^VI/SAPO-11composite desulfurization yield more than twice the yield of pure mesoporous SAPO-11 samples due to the synergistic effect of molybdenum oxide and molecular sieve secondary pores.At the same time,the effects of different templating agents and different crystal phases of molybdenum oxide on the activity of the catalyst were investigated.?2?Secondly,the synthesized Mo^VI/SAPO-11 composite was applied to the Baeyer-Villiger oxidation reaction to further test the catalytic performance.The experimental results showed that our catalyst?-Mo^VI/C2-S-11-3.6 for the oxygen utilization rate is very high in the air,and under the optimal reaction conditions?reaction temperature 50°C,5h,reaction solvent:EtOAc,oxidant is air?,the catalyst?-Mo^VI/C2-S-11-3.6for the B-V oxidation reaction of the six-member ring ketone exhibits high yield and good durability.Then,the ODS reaction and Baeyer-villiger oxidation reaction products were determined by GC-MS and ¹H NMR.