A mesoporous(d=2.3mm)silica-pillared layered tetratita nate with a super gallery(d 001 =1.84mm)was prepared by first preswelling layered tetratitanate with n-dodecyl amine,then reacting with 20wt%NH 2 (CH 2 ) 3 Si (OC...A mesoporous(d=2.3mm)silica-pillared layered tetratita nate with a super gallery(d 001 =1.84mm)was prepared by first preswelling layered tetratitanate with n-dodecyl amine,then reacting with 20wt%NH 2 (CH 2 ) 3 Si (OC 2 H 5 ) 3 aqueous solution,and finally calcinating the resultant solid product i n air at 550℃.All the reaction was carried out hydrothermally in an aut oclave at 130℃.The obtained materia l has a relatively high BET surface area of204m 2 ·g -1 and a thermal stability beyond 600℃.The catalytic application of the material was also investigated by using the dehydration of isopropanol and the reform of n-hexane as two probing reactions.展开更多
Octa(tetramethylammonium)-polyhedral oligomeric silsesquioxane(TMA-POSS) with cage-like structure was synthesized, the structure was characterized by NMR, FTIR and Elemental analyses. The mesoporous silica was prepare...Octa(tetramethylammonium)-polyhedral oligomeric silsesquioxane(TMA-POSS) with cage-like structure was synthesized, the structure was characterized by NMR, FTIR and Elemental analyses. The mesoporous silica was prepared under alkaline condition using TMA-POSS as the silicon source and hexadecyltrimethylammonium bromide (CTAB) as the template, the structures of these products were characterized by XRD, TEM and nitrogen adsorption and desorption methods. The results indicate that the synthesized silica exhibites a well-ordered hexagonal pore structure with larger specific surface area. With increasing of CTAB molar ratio, the spacing of the crystal plane d100 is increased. The effects of the pH values on the mesoporous structure in the reaction system with different molar ratio of nPOSS / nCTAB were investigated. The synthesis mechanism of mesoporous silica was also discussed.展开更多
文摘A mesoporous(d=2.3mm)silica-pillared layered tetratita nate with a super gallery(d 001 =1.84mm)was prepared by first preswelling layered tetratitanate with n-dodecyl amine,then reacting with 20wt%NH 2 (CH 2 ) 3 Si (OC 2 H 5 ) 3 aqueous solution,and finally calcinating the resultant solid product i n air at 550℃.All the reaction was carried out hydrothermally in an aut oclave at 130℃.The obtained materia l has a relatively high BET surface area of204m 2 ·g -1 and a thermal stability beyond 600℃.The catalytic application of the material was also investigated by using the dehydration of isopropanol and the reform of n-hexane as two probing reactions.
文摘Octa(tetramethylammonium)-polyhedral oligomeric silsesquioxane(TMA-POSS) with cage-like structure was synthesized, the structure was characterized by NMR, FTIR and Elemental analyses. The mesoporous silica was prepared under alkaline condition using TMA-POSS as the silicon source and hexadecyltrimethylammonium bromide (CTAB) as the template, the structures of these products were characterized by XRD, TEM and nitrogen adsorption and desorption methods. The results indicate that the synthesized silica exhibites a well-ordered hexagonal pore structure with larger specific surface area. With increasing of CTAB molar ratio, the spacing of the crystal plane d100 is increased. The effects of the pH values on the mesoporous structure in the reaction system with different molar ratio of nPOSS / nCTAB were investigated. The synthesis mechanism of mesoporous silica was also discussed.
