Effect of surface acidity and pore size of Al-substituted plugs-containing SBA-15 and MCM-41 silicas

来源 :Chinese Chemical Letters | 被引量 : 0次 | 上传用户:wanshanshan1989
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We reported here the simultaneous influence of surface acidity and pore size of Al-substituted hexagonal mesoporous silicas(Al-doped plugs-containing SBA-15 and Al-doped MCM-41) on polymerization of THF.These materials were directly synthesized by introduced aluminum isopropoxide into reaction mixture including surfactant and siliceous precursor.Al-doped plugs-containing SBA-15(denotes as PAS) samples not only possess typical two-step desorption isotherms,which implied PAS materials generated plugs in their mesochannel,but also exhibit larger pore size and thicker wall than that of Al-doped MCM-41(denotes as ACM), which implied PAS would have a great advantage on catalytic reaction involving large molecular(e.g.polymer of THF) in industrial point of view.To investigate catalytic activity of PAS and ACM with moderate acidic sites the polymerization of THF in the presence of acetic anhydride was carried out.The results showed PAS exhibiting good performance on polymerization of THF.Such result could be related to the large pore size and moderate acidic sites. We reported here the simultaneous influence of surface acidity and pore size of Al-substituted hexagonal mesoporous silicas (Al-doped plugs-containing SBA-15 and Al-doped MCM-41) on polymerization of THF. The materials were directly synthesized by introduced aluminum isopropoxide into reaction mixture including surfactant and siliceous precursor. Al-doped plugs-containing SBA-15 (indicated as PAS) samples not only possess typical two-step desorption isotherms, which implied PAS materials generated plugs in their mesochannel, but also larger size and thicker wall than that of Al-doped MCM-41 (indicating as ACM), which implied PAS would have a great advantage on catalytic reaction involving large molecular (egpolymer of THF) in industrial point of view. To investigate catalytic activity of PAS and ACM with moderate acidic sites the polymerization of THF in the presence of acetic anhydride was carried out. The results showed PAS exhibiting good performance on polymerization of THF. Such result could be related to the large pore size and moderate acidic sites.
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