Co-or Mn-substituted LTL zeolites were hydrothermally synthesized by a novel organic-ligand-assisted method.XRD,UVVis DRS,XPS,and EPR techniques verified that the Co and Mn ions were incorporated into the zeolite fram...Co-or Mn-substituted LTL zeolites were hydrothermally synthesized by a novel organic-ligand-assisted method.XRD,UVVis DRS,XPS,and EPR techniques verified that the Co and Mn ions were incorporated into the zeolite framework.No organic species were retained in as-synthesized Co or Mn-LTL zeolites,which resulted in porous materials without calcination.In the oxidation of cyclohexane with tert-butyl hydroperoxide(TBHP),the Co-LTL and Mn-LTL gave a 40%–48%KA oil(cyclohexanone and cyclohexanol)yield as well as nearly 100%TBHP conversion under mild reaction conditions.The reactions were confirmed to be heterogeneous and to have proceeded catalytically.No loss of catalytic activity or leaching of metal active sites ions were observed during 4 reuses.展开更多
A Yarge-pore ECNU-19 material with unique pore system consisting of 12-ring （12R） pore channels intersected by 8R channels was post-synthesized via interlayer-expansion of HUS-2 lameliar silicate with silylating age...A Yarge-pore ECNU-19 material with unique pore system consisting of 12-ring （12R） pore channels intersected by 8R channels was post-synthesized via interlayer-expansion of HUS-2 lameliar silicate with silylating agent of 1,3-dimethyltetramethoxydisiloxane （DMTMDS）. In consideration of the fact that the HUS-2 precursor possessed a special structure with a malposition of the neighboring layers as well as silicon vacancies on layer surface, a ＂detemplating disassembly - intercalation reassembly - silylation＂ strategy was proposed to realize a successful interlayer-expansion and structural amending. An acid treatment was firstly performed to remove a part of the structure-directing agent molecules, which favored the following intercalation by bulk organic species. The intercalation not only rearranged the relative position of up-down layers but also provided enough interlayer space for the insertion of dimeric silane molecules. Two -OH groups attached to one silicon atom of the silane molecule reacted with two close silanols on the up-surface layer, while the other two -OH groups condensed with two silanols on the down-surface layer, which then connected the two layers via -Si-O-Si- pillars and constructed new 22R pores along o axis and 8R pores along c axis, respectively.展开更多
基金supported by the National Natural Science Foundation of China(21373089,U1162102)the PhD Programs Foundation of the Ministry of Education(2012007613000)+1 种基金the National Key Technology R&D Program(2012BAE05B02)the Shanghai Leading Academic Discipline Project(B409)
文摘Co-or Mn-substituted LTL zeolites were hydrothermally synthesized by a novel organic-ligand-assisted method.XRD,UVVis DRS,XPS,and EPR techniques verified that the Co and Mn ions were incorporated into the zeolite framework.No organic species were retained in as-synthesized Co or Mn-LTL zeolites,which resulted in porous materials without calcination.In the oxidation of cyclohexane with tert-butyl hydroperoxide(TBHP),the Co-LTL and Mn-LTL gave a 40%–48%KA oil(cyclohexanone and cyclohexanol)yield as well as nearly 100%TBHP conversion under mild reaction conditions.The reactions were confirmed to be heterogeneous and to have proceeded catalytically.No loss of catalytic activity or leaching of metal active sites ions were observed during 4 reuses.
文摘A Yarge-pore ECNU-19 material with unique pore system consisting of 12-ring （12R） pore channels intersected by 8R channels was post-synthesized via interlayer-expansion of HUS-2 lameliar silicate with silylating agent of 1,3-dimethyltetramethoxydisiloxane （DMTMDS）. In consideration of the fact that the HUS-2 precursor possessed a special structure with a malposition of the neighboring layers as well as silicon vacancies on layer surface, a ＂detemplating disassembly - intercalation reassembly - silylation＂ strategy was proposed to realize a successful interlayer-expansion and structural amending. An acid treatment was firstly performed to remove a part of the structure-directing agent molecules, which favored the following intercalation by bulk organic species. The intercalation not only rearranged the relative position of up-down layers but also provided enough interlayer space for the insertion of dimeric silane molecules. Two -OH groups attached to one silicon atom of the silane molecule reacted with two close silanols on the up-surface layer, while the other two -OH groups condensed with two silanols on the down-surface layer, which then connected the two layers via -Si-O-Si- pillars and constructed new 22R pores along o axis and 8R pores along c axis, respectively.
