61434-46-6Relevant articles and documents
The isopropylation of biphenyl over transition metal substituted aluminophosphates: MAPO-5 (M: Co and Ni)
Zhang, Hui Xing,Chokkalingam, Anand,Subramaniam, Priya V.,Joseph, Stalin,Takeuchi, Seiji,Wei, Ming Deng,Al-Enizi, Abdullah M.,Jang, Hoi-Gu,Kim, Jong-Ho,Seo, Gon,Komura, Kenichi,Sugi, Yoshihiro,Vinu, Ajayan
, p. 117 - 124 (2016/01/26)
The isopropylation of biphenyl (BP) was examined over transition metal substituted aluminophosphates (MAPO-5; M: Co and Ni) with 12-membered (12-MR) oxygen ring pore-entrances of AFI topology. The MAPO-5 samples were synthesized by dry gel conversion method using trimethylamine as a structure directing agent, and their properties were characterized by XRD, XPS, SEM, N2 adsorption, NH3-TPD, pyridine adsorption, and o-xylene uptake. They are clear crystals without impurity phases and agglomerates, and found small amounts of Br?nsted acid sites which are expecting active for acid catalysis. The isopropylation of BP over both of Co(5)APO-5 and Ni(5)APO-5 at 250 °C gave the high selectivities for 4,4′-DIPB: 65-75%. 4-IPBP is almost exclusive precursor of 4,4′- and 3,4′-DIPB. 3-IPBP was not significantly concerned even though 3-IPBP was predominant among IPBP isomers at the late stages: the MAPO-5 channels allow preferential access of 4-IPBP, and prevent the access of 3-IPBP due to reactant selectivity mechanism. The selective formation of 4,4′-DIPB occurred by preferential exclusion of bulkier 3,4′-DIPB and other isomers through the steric interaction of transition states with the channels by the restricted transition state selectivity mechanism. MAPO-5 (M: Co and Ni) has the same level of the selectivities for 4,4′-DIPB to SSZ-24 and other MAPO-5 (M: Si, Mg, and Zn), and these selectivities were originated by the AFI channels. The selectivities for 4,4′-DIPB were kept 65-75% at low and moderate temperatures over MAPO-5 (M: Co and Ni); however, they were decreased by the isomerization to stable 3,4′-DIPB with the increase in temperature.
Isopropylation of biphenyl over ZSM-12 zeolites
Chokkalingam, Anand,Kawagoe, Hiroaki,Watanabe, Seiji,Moriyama, Yasuhiro,Komura, Kenichi,Kubota, Yoshihiro,Kim, Jong-Ho,Seo, Gon,Vinu, Ajayan,Sugi, Yoshihiro
, p. 23 - 30 (2013/02/23)
ZSM-12 zeolites, ZSM-12L and ZSM-12S, with MTW topology were synthesized by using methyltriethylammonium bromide (MTEABr) and tetraethylammnoium bromide (TEABr) as structure directing agents (SDA), respectively, for the isopropylation of biphenyl (BP) usi
Shape-selective alkylation of biphenyl over H-[Al]-SSZ-24 zeolites with AFI topology
Ito, Akira,Maekawa, Hiroyoshi,Kawagoe, Hiroaki,Komura, Kenichi,Kubota, Yoshihiro,Sugi, Yoshihiro
, p. 215 - 223 (2008/02/10)
H-[Al]-SSZ-24 zeolites with AFI topology were synthesized through the alumination of [B]-SSZ-24 zeolites, and applied for the alkylation of biphenyl (BP). H-[Al]-SSZ-24 zeolites have high activity for the isopropylation. The shape-selective formation of 4,4′-diisopropylbiphenyl (4,40-DIPB) occurred at moderate temperature; however, the selectivity for 4,40-DIPB decreased with an increase in the reaction temperature. Isomerization of 4,4′-DIPB occurred at higher temperatures over internal and external acid sites when there are enough acid sites inside the channels. The channels can discriminate 4,4′-DIPB from the other DIPB isomers in their transition states; however, they can not prevent the isomerization of 4,4′-DIPB at higher temperatures. The selectivity for the least bulky 4,4′-dialkylbiphenyl increased with the bulkiness of alkylating agents in the order: isopropylation s-butylation t-butylation. These results strongly support the shape-selective formation of the least bulky products inside the channels of H-[Al]-SSZ-24 zeolites.