Shijian Liao

Bio: Shijian Liao is an academic researcher from Dalian Institute of Chemical Physics. The author has contributed to research in topics: Catalysis & Palladium. The author has an hindex of 6, co-authored 6 publications receiving 176 citations.

Hydrogenation of nitroaromatics by polymer-anchored bimetallic palladium-ruthenium and palladium-platinum catalysts under mild conditions

Abstract: Polymer-achored monometallic palladium catalyst PVP-PdCl2 (PVP = poly(N-vinyl-2-pyrrolidone)) exhibits very high activity for the hydrogenation of p-chloronitrobenzene (CNB) to aniline (AN) in the presence of base at 65°C and atmospheric pressure. In this case, the substrate is rapidly hydrodechlorinated to nitrobenzene (NB) which is then reduced to AN. Using the polymer-anchored bimetallic palladium-ruthenium catalyst, PVP-PdCl2-RuCl3, and in the presence of 1.0 mol% of sodium acetate, a strong synergic effect gives rise to a remarkable increase of the selectivity for p-chloroaniline (CAN) and the maximum selectivity of CAN is up to 94%. For the hydrogenation of the non-halo-substituted nitroaromatics to the corresponding aromatic amines, the monometallic PVP-PdCl2 catalyst only shows mild or poor activity, but the colloidal polymer-anchored bimetallic palladium-platinum catalyst, PVP-Pd-1 4Pt , exhibits very high activity and selectivity.

A remarkable synergic effect of polymer-anchored bimetallic palladium–ruthenium catalysts in the selective hydrogenation of p-chloronitrobenzene

Abstract: A synergic effect of the polymer-anchored bimetallic palladium-ruthenium catalysts can lead to a remarkable increase in the selectivity for p-chloroaniline in the selective hydrogenation of p-chloronitrobenzene under atmospheric pressure and in the presence of a small amount of base.

Synergic effect of palladium-based bimetallic catalysts for the hydrogenation of nitroaromatics

Abstract: Bimetallic catalysts, PdCl2-MXn and PdCl2(PhCN)2-Mxn (MXn=FeCl3, Fe(acac)3, Co(OAc)2, CoCl2, Co(acac)2, NiCl2, Ni(OAc)2, RuCl3, Cu(OAc)2, CuCl2), exhibit remarkable synergic effect which can obviously increase the activity of the monometallic Pd catalyst for the hydrogenation of nitroaromatics, whereas MXn alone is not catalytically active under the same reaction conditions

Facile hydrodebromination of organic bromides with dihydrogen and polymer-anchored palladium catalyst under mild conditions

Abstract: The hydrodebromination of organic bromides with dihydrogen and the soluble polymer-anchored palladium catalyst PVP-PdCl 2 (PVP = poly(N-vinyl-2-pyrrolidone)) was effectively carried out in ethanol by using sodium acetate as the base and at 60°C and atmospheric pressure. This catalyst exhibited very high catalytic activity, selectivity and efficiency for the hydrodebromination of aromatic bromides and some aliphatic bromides. The selectivities of the products for the hydrodebromination of benzyl bromide and ω-bromoacetophenone were obviously increased by means of the soluble polymer-anchored bimetallic catalyst PVP-PdCl 2 -RuCl 3 . It was found that the poisoning effect of halogen ions can lead to a decrease of the catalytic activity and deactivation of the catalyst in some cases. Two types of neighboring group participation are proposed to account for the strong substituent effect of the ortho- and meta-substituted aromatic bromides in their hydrodebromination.

Catalytic behaviors and gas permeation properties of palladium‐containing phenophthalein poly(ether sulfone)

Abstract: Palladiumsupported on a high-temperature-withstanding polymer, phenophthalein poly(ether sulfone) (PES-C), exhibits very high catalytic activity both in the carbonylation of allyl bromide and in the hydrogenation of 1-octene at 40°C and atmospheric pressure. The initial activities are up to 345 mol CO/mol Pd min and 493 mol H2/mol Pd min, respectively. The polymer-supported palladium catalysts prepared by refluxing the mixture of PdCl2 and PES-C immersed in benzene/ethanol (1/3, v/v) prior to the preparation of the catalyst show higher catalytic activity than those obtained by refluxing the mixture of PdCl2 and PES-C in benzene/ethanol. The Pd-containing PES-C membranes made from the polymer-supported palladium catalysts are endowed with a very specific permeability of H2 and the corresponding Pd-containing membrane catalysts can also exhibit considerable catalytic activity for the hydrogenation of 1-octene. © 1996 John Wiley & Sons, Inc.

Innovations in palladium membrane research

Abstract: This review highlights various aspects of current palladium membrane research and serves as a comprehensive bibliography covering palladium membrane preparation methods and applications. There are many promising uses for palladium membranes, although widespread use of the available technologies is constrained primarily by the high cost of palladium, lack of durability due to hydrogen embrittlement, and susceptibility to fouling. Various researchers in the field are tackling these problems and fabricating thinner palladium alloy composite membranes that better withstand contaminantion and thermal cycling. What has been accomplished to address these issues and the directions presently being explored are discussed.

Catalysis by metal nanoparticles supported on functional organic polymers

Abstract: The preparation and catalytic applications of dispersed metal catalysts supported on organic functional polymers are presented. The advantages of these catalysts, such as the easy tailoring with respect to the nature of the used support, the “nanoscale” size control of metal crystallites by the polymer framework, the high accessibility and consequent catalytic activity in a proper liquid or liquid–vapor reaction systems are stressed. Various proposed catalytic processes making use of these materials are presented and evaluated, including multifunctional catalysis, e.g. redox-acid. Interesting peculiar aspects such as the enhancement of the hydrogenation rate by nitrogen containing moieties anchored to the polymer backbone are emphasised. When suitable, a comparison with catalysts based on inorganic supports is given.