2568-25-4Relevant articles and documents
One-step preparation of flower-like poly(styrene-co-zwitterionic ionic liquid) microspheres with hierarchical structures for supported acidic heterogeneous catalysts
Mao, Hui,Song, Yang,Qian, Dongmei,Liu, Daliang,Wu, Shuyao,Zhang, Yu,Hisaeda, Yoshio,Song, Xi-Ming
, p. 91654 - 91664 (2015)
By using a one-step copolymerization of styrene (St) and 3-(1-vinyllimidazolium-3-yl)propane-1-sulfonate (VIPS), a kind of poly(St-co-VIPS) microsphere, with a hierarchical structure composed of nanospheres or nanoparticles with diameters in the range of 70-90 nm arranged on its surface and that look like a flower, has been simply prepared in the presence of polyvinyl pyrrolidone (PVP) in an aqueous alcohol system. A formation mechanism of the flower-like poly(St-co-VIPS) microspheres is proposed by investigating the influence of reaction conditions on its morphologies and observing its growth process with time. Because of the existence of zwitterionic liquid functional groups, flower-like poly(St-co-VIPS)-acid microspheres, a novel kind of heterogeneous catalyst, were successfully prepared by immobilizing heteropoly acids and H2SO4 on the flower-like poly(St-co-VIPS) microspheres, and the heterogeneous catalysts showed better catalytic activities for esterifications, acetalizations and transesterifications than with H2SO4 as the catalyst. Especially, the heterogeneous catalysts presented excellent catalytic efficiency for the acetalization of benzaldehyde and 1,2-propanediol, which could successfully reach 96.2%. Furthermore, the crosslinked flower-like poly(DVB-co-VIPS)-H2SO4 microspheres prepared under the same conditions where only St was replaced by divinyl benzene (DVB) have better reusability than that of the flower-like poly(St-co-VIPS)-H2SO4 with poor solvent resistance, and could be reused four times without significant loss of the catalytic activity, indicating that they could act as excellent recyclable heterogeneous catalysts for the synthesis of acetals and have potential application in industry.
Soluble/MOF-Supported Palladium Single Atoms Catalyze the Ligand-, Additive-, and Solvent-Free Aerobic Oxidation of Benzyl Alcohols to Benzoic Acids
Tiburcio, Estefanía,Greco, Rossella,Mon, Marta,Ballesteros-Soberanas, Jordi,Ferrando-Soria, Jesús,López-Haro, Miguel,Hernández-Garrido, Juan Carlos,Oliver-Meseguer, Judit,Marini, Carlo,Boronat, Mercedes,Armentano, Donatella,Leyva-Pérez, Antonio,Pardo, Emilio
supporting information, p. 2581 - 2592 (2021/02/16)
Metal single-atom catalysts (SACs) promise great rewards in terms of metal atom efficiency. However, the requirement of particular conditions and supports for their synthesis, together with the need of solvents and additives for catalytic implementation, often precludes their use under industrially viable conditions. Here, we show that palladium single atoms are spontaneously formed after dissolving tiny amounts of palladium salts in neat benzyl alcohols, to catalyze their direct aerobic oxidation to benzoic acids without ligands, additives, or solvents. With this result in hand, the gram-scale preparation and stabilization of Pd SACs within the functional channels of a novel methyl-cysteine-based metal-organic framework (MOF) was accomplished, to give a robust and crystalline solid catalyst fully characterized with the help of single-crystal X-ray diffraction (SCXRD). These results illustrate the advantages of metal speciation in ligand-free homogeneous organic reactions and the translation into solid catalysts for potential industrial implementation.
Method for improving activity of propylene epoxide catalyst and co-producing ketal (acetal)
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Paragraph 0020; 0037; 0038; 0039, (2019/01/17)
The invention provides a method for synthesizing propylene epoxide and co-producing ketal (acetal) by taking a by-product PG as a raw material in propylene epoxidation in the presence of heteropoly acid as a catalyst. Negative effects of alcohol substances to the activity of the catalyst in epoxidation reaction are eliminated, the activity of the catalyst is improved, the catalyst is used stably,meanwhile, downstream application of the by-product PG is expanded, and a preparation method for ketal (acetal) is provided. The method has the advantages of gentle reaction conditions, good catalyzing stability, good catalyst using effect, and resource utilization of the by-product.
