机构地区:[1]College of Chemistry and Molecular Engineering,Nanjing Tech University,Nanjing 211816,Jiangsu,China [2]Research institute of QILU petrochemical company,SINOPEC,Zibo 255400,Shandong,China [3]Key Laboratory of Mesoscopic Chemistry of MOE,School of Chemistry and Chemical Engineering,Nanjing University,Nanjing 210023,Jiangsu,China [4]School of Chemical Engineering,Shandong University of Technology,Zibo 255049,Shandong,China
出 处:《Chinese Journal of Catalysis》2018年第5期955-963,共9页催化学报(英文)
基 金:国家重点研究发展计划项目(2016YFB0301703);江苏省产学研前瞻性联合研究项目(BY2016005-06);国家自然科学基金(21506118).
摘 要:Mesoporous superacids S2O82–-Fe2O3/SBA-15(SFS)with active nanoparticles are prepared by ultrasonic adsorption method.This method is adopted to ensure a homo-dispersed nanoparticle active phase,large specific surface area and many acidic sites.Compared with bulk S2O82–-Fe2O3,Br?nsted acid catalysts and other reported catalysts,SFS with an Fe2O3 loading of 30%(SFS-30)exhibits an outstanding activity in the probe reaction of alcoholysis of styrene oxide by methanol with 100%yield.Moreover,SFS-30 also shows a more excellent catalytic performance than bulk S2O82–-Fe2O3 towards the alcoholysis of other ROHs(R=C2H5-C4H9).Lewis and Bronsted acid sites on the SFS-30 surfaces are confirmed by pyridine adsorbed infrared spectra.The highly efficient catalytic activity of SFS-30 may be attributed to the synergistic effect from the nano-effect of S2O82–-Fe2O3 nanoparticles and the mesostructure of SBA-15.Finally,SFS-30 shows a good catalytic reusability,providing an 84.1%yield after seven catalytic cycles.摘要:酸催化剂在化学反应和化工生产中具有重要的作用.传统无机酸,如H_2SO_4,H_3PO_4和对甲苯磺酸等具有较高的催化活性,但是存在污染大、设备腐蚀严重以及催化剂不能重复使用等问题.固体酸具有酸性强、易分离、环境友好以及稳定性和重复使用性好等特点因而近年来越来越引起人们的关注.其中,SO_4^(2-)-M_xO_y固体超强酸(如SO_4^(2-)-Zr O_2,SO_4^(2-)-Ti O_2和SO_4^(2-)-Sn O_2等)因具有很好的催化性能而备受关注.相比SO_4^(2-)-M_xO_y,S_2O_8^(2-)-M_xO_y具有更强的酸性和稳定性而成为研究的重点.如何克服固体超强酸本体的低比表面积和孔容,增加其比表面积和催化活性是固体超强酸研究的热点.超声吸附法可保证所制介孔固体酸活性组分均匀分散,以及大的比表面积和更多的酸性位点.因此采用超声吸附法制备了一种新型介孔固体酸S_2O_8^(2-)-Fe_2O_3/SBA-15.相比S_2O_8^(2-)-Fe_2O_3本体、B酸和文献报道催化剂,负载30%Fe_2O_3的S_2O_8^(2-)-Fe_2O_3/SBA-15在环氧苯乙烷甲醇醇解的探针反应中显示出很高的催化活性,反应收率为100%.S_2O_8^(2-)-Fe_2O_3纳米粒子的纳米效应和SBA-15介孔结构的协同作用使S_2O_8^(2-)-Fe_2O_3/SBA-15具有高催化活性.相比S_2O_8^(2-)-Fe_2O_3本体,采用超声分散技术制备的S_2O_8^(2-)-Fe_2O_3/SBA-15固体超强酸具有典型的介孔结构、大的比表面积和孔容,并且表面富含酸性位点.并且吡啶红外分析S_2O_8^(2-)-Fe_2O_3/SBA-15表面富含L酸和B酸.环氧苯乙烷甲醇醇解探针反应表明,Fe_2O_3负载量为30%时,S_2O_8^(2-)-Fe_2O_3/SBA-15的催化活性最高,优于S_2O_8^(2-)-Fe_2O_3本体和已报道的布朗酸和路易斯酸等催化剂,将醇底物拓展(ROHs,R=C_2H_5-C_4H_9),S_2O_8^(2-)-Fe_2O_3/SBA-15的催化活性也优于S_2O_8^(2-)-Fe_2O_3本体.同时,S_2O_8^(2-)-Fe_2O_3/SBA-15具有很好的重复使用性能,连续使用七次,反应收率在84.1%以上.总之,具有高催化活性、好的�
关 键 词:Mesoporous superacid Nanoparticle Nano effect S2O82–-Fe2O3/SBA-15 Acidic site Ultrasonic adsorption ALCOHOLYSIS
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