Preparation Of NH₂/SH-bifunctional Mesoporous Solid Catalyst And Study On Their Properties Of Catalysis

Acid-base cooperative function is widely used in the field ofenzyme and antibody. Its characteristic of organism catalysis hasalready attracted a lot of chemical workers to pursue to synthesize newbifunctional or multifunctional catalysis. This kind of catalyst don’t havemetal, catalytic activity, high stereoselectivity or gentle reactioncondition，but as two kinds of fully different group, it is a hard topic forresearcher to make acid and base no neutralization reaction andcatalyze effectively in the process of preparation and use. In thefield of industrial catalysis, mesoporous is known as catalyst or catalysissupporter. But immobilizing acid and base group in the same supportercan avoid the possibility of neutralization of acid-base and formacid-base bifunctional catalyst. It also can separate from the productconveniently, recover and reuse which accords with green chemistry.In the research of inhomogeneous catalytic supporter, mesoporousmaterials are the most common and popular. SBA-15, as one of thewidest mesoporous materials, has its characteristic: highly order, thepore canal well-distributed, the big superficial area. And it has differentshape according to different need, the pore diameter can becontrolled. Thermostability and hydrothermal stability are good, thegroups of materials surface can be modified. In terms ofmacromolecule catalysts, preferential adsorption and functionalmaterials, it has extensive applied prospects. So taking advantage ofthose characteristic, we mainly develop achirality acid-basebifunctional catalyst, which choose SBA-15as supporter, and try tomake a research about its catalytic properties. However, for alarge proportion of solid acid-base bifunctional catalysts, their acid andbase groups disperse in the material surface randomly and disorderly,which couldn’t have good catalytic effect. So we adopt a novelty “first bonding second separating” method. Firstly, we synthesize organicsilica compound, then using the method of co-condensation,polymerize with SBA-15, then use the method of thermolysis ofcarbamates, in the temperature of250℃,protected with N2that couldbreak amino and thiol, in that way, amino and thiol can arrange nearlycontribute to cooperative reaction. We compose three differentconcentration catalyst and one kind of random ratio of amino and thiolcatalyst, then we use in the reaction of Henry and Knoevenagel. Thereaction result is better when use the1:1arranged catalyst, theeffective is above99%. Postgrafting could block the hole of the catalyst,so the effective is not so good. Above in all, we know that according tothe method of cocondesation, the catalyst is the best. We also usedifferent aldehyde to test the catalyst, the effective is almost above90%.Thirdly, cracking in high temperature to break amino and thiol,which could make amino and thiol distribute nearly to synthesizedifferent ratio of amino and thiol to compare. At last we will use thosecatalysts to catalyze Henry reaction and Knoevenagel reaction, they allhave well catalytic effect.