Anchoring sulfonic acid on silica surface through Si C bond for immobilization of catalyst for polyketone synthesis
摘要:
Sulfonic acid groups were anchored on a silica surface through robust Si-C bonds. The successive treatment of dehydroxylated silica with benzylmagnesium chloride and H2SO4 resulted in the surface tethering of -CH2C6H4SO3H groups at a high coverage rate (0.50-CH2C6H4SO3H/nm(2)). The pore structure of the silica remained unchanged during this surface-modification process. Next, the -CH2C6H4SO3H groups on the surface were successfully used for preparing a supported catalyst for CO/ethylene copolymerization; the Si-CH2C6H4SO3H groups on the surface were reacted with [1,3-bis(di(2-methoxyphenyl)phosphino)propane]Pd-( OAc)(2) to generate dicationic palladium species, which were anchored on the silica surface through ionic interactions with the sulfonate anions generated on the surface. The supported catalyst prepared in this way exhibited a high activity (up to 43 kg/g-Pd or 0.61 kg/g-cat) with respect to CO/ethylene copolymerization. The morphology of the obtained polymer particles replicated that of the silica particles. Thus, a polymer powder that exhibited a high bulk density (0.30 g/mL) could be obtained while causing minimal reactor fouling. (C) 2015 Elsevier B.V. All rights reserved.
Palladium complex catalysed synthesis of sulfinic acids, sulfinic acid esters, sulfonic acids and S-alkyl alkanethiosulfonates
作者:Jürgen Herwig、Wilhelm Keim
DOI:10.1016/0020-1693(94)03911-9
日期:1994.7
Abstract A novel reaction for the synthesis of sulfinicacids, sulfinicacidsesters, sulfonicacids and S -alkyl alkanethiosulfonates from olefins, SO 2 and hydrogen will be described. Due to its similarity to hydroformylation, this reaction will be called hydrosulfination. Various palladiumcomplexes ([Pd(NCCH 3 ) 2 (R 2 P(CH 2 ) n PR 2 )](BF 4 ) 2 (RPh, n =2–5; RMe, o -(C 6 H 4 OMe), n =3) have
CO-ethylene copolymerization reactions in different reaction media catalyzed by palladium(II) complexes with chelating diphosphines bearing ortho-methoxy-substituted aryl groups
作者:Claudio Bianchini、Andrea Meli、Werner Oberhauser、Anna M. Segarra、Carmen Claver、Eduardo J. Garcia Suarez
DOI:10.1016/j.molcata.2006.10.035
日期:2007.3
Neutral and bis-cationic palladium(H) complexes with 1,2-bis(di(2-methoxyphenyl)phosphino)ethane (o-MeO-dppe) and 1,3-bis(di(2-methoxyphenyl)phosphino)propane (o-MeO-dppp) have been synthesized and employed to catalyze the CO-ethylene copolymerization reaction in either protic or aprotic solvents. A comparison of the catalytic performance of these complexes with that of analogous precursors stabilized by 1,2-bis(diphenylphosphino)ethane (dppe) and 1,3-bis(diphenylphosphino)propane (dppp) ligands has shown significant differences in terms of catalytic productivity and molecular weight. In situ and operando high-pressure NMR experiments have provided valuable information on catalysis resting states and intermediates and have contributed to rationalize the observed productivity as well. (c) 2006 Elsevier B.V. All rights reserved.
Influence of the operating conditions on the catalytic activity of [PdCl2(dapp)] in the CO–ethene copolymerization in the H2O–CH3COOH as a solvent (dapp=1,3-bis(di(2-methoxyphenyl)phosphino)propane)
The influence on the productivity of[PdCl2(dapp)] in H2O-CH3COOH in the CO-ethene copolymerization and on the LVN of the copolymer of the following reaction parameters has been studied: (i) composition of the H2O-CH3COOH reaction medium; (ii) temperature; (iii) CO/ethene ratio at a given total pressure; (iv) total pressure at fixed ratio CO/ethene = 1/1; (v) CO or ethene partial pressure at a given pressure of one monomer; (vi) reaction time. High molecular weight PKs are obtained under high pressure with the monomers in the ratio 1/1 at relatively low temperature and with a H2O/CH3COOH 40-50% with productivity ranging from 4 to 20 kg PK(g Pd h)(-1).The relation between productivity and LVN has been discussed in the light of the key steps of the catalytic cycle. (C) 2010 Elsevier B.V. All rights reserved.