催化羰化合成丙二酸及其衍生物

以合成基础化学品为目的的C_1化学。近年来在合成精细化学品方面也取得明显的进步。本文概述了在过渡金属络合物的催化作用下,卤代乙酸酯经羰化反应合成为丙二酸酯的研究概况、反应机理及有关因素的影响。

Study on Direct Synthesis of Diphenyl Carbonate with Heterogeneous Catalytic Reaction (V) Screening Catalysts and Optimizing Synthesis Conditions

Pd/LaxPbyMnOz, Pd/C, Pd/molecular sieve and Pd-heteropoly acid catalysts for direct synthesis of diphenyl carbonate (DPC) by heterogeneous catalytic reaction were compared and the results of DPC synthesis indicated that the catalyst Pd/LaxPbyMnOz had higher activity. The Pd/LaxPbyMnOz catalyst and the support was characterized by XRD, SEM and TEM, the main phase was Lao.szPbo.asMnOa and the average diameter could be about 25.4nm. The optimuna conditions for synthesis of DPC with Pd/LasPbyMnOz were determined by orthogonal experiments and the experimental results showed that reaction temperature was the first factor of effect on the selectivity and yield of DPC, and the concentration of O2 in gas phase also had significant effect on selectivity of DPC. The optimum reaction conditions were catalyst/phenol mass ratio l to 50, pressure 4.5MPa, volume concentration of O2 25%, reaction temperature 60℃ and reaction time 4 h. The maximum yield and average selectivity could reach 13% and 97% respectively in the batch operation.

Tuning the growth of Cu-MOFs for efficient catalytic hydrolysis of carbonyl sulfide

Development of the high activity,promoter‐free catalysts for carbonyl sulfide(COS)hydrolysis is important for the efficient utilization of various feedstocks.In this study,the Cu‐based metal‐organic framework HKUST‐1is synthesized by a simple and mild anodic‐dissolution electrochemical method.The physical and chemical properties of the samples are characterized by several techniques,including scanning electron microscopy,X‐ray diffraction,Brunauer‐Emmett‐Teller analysis and X‐ray photoelectron spectroscopy.The results reveal that the synthesis voltage plays a crucial role in controlling the morphology of the resulting HKUST‐1.The obtained samples function as novel catalysts for the hydrolysis of COS.A high efficiency,approaching100%,can be achieved for the conversion of COS at150oC over the optimal HKUST‐1synthesized at25V.This is significantly higher than that of the sample prepared by the traditional hydrothermal method.Additionally,the effects of the water temperature and the flow velocity on the hydrolysis of COS are also investigated in detail.Finally,a possible reaction pathway of COS hydrolysis over HKUST‐1is also proposed.This work represents the first example of MOFs applied to the catalytic hydrolysis of COS.The results presented in this study can be anticipated to give a feasible impetus to design novel catalysts for removing the sulfur‐containing compounds.

Synthesis of a Novel Solid Acid with both Sulfonic and Carbonyl Acid Groups and Its Catalytic Activities in Acetalization

The novel solid acid with both sulfonic and carbonyl acid groups has been synthesized from 3-((2-sulfoethoxy) carbonyl)acrylic acid and tetraethyl orthosilicate(TEOS). The catalytic activities were investigated through the acetalization. The results showed that the novel solid acid was very efficient for the reactions with the high yields. The high acidity, high stability and reusability were the key feature of the novel solid acid. Moreover, the sulfonic and carbonyl acid groups could cooperate during the catalytic process, which improved its catalytic activities. The catalyst shows recyclability, and hold great potential for replacement of homogeneous catalysts.

Synthesis of Diphenyl Carbonate over the Magnetic Catalysts Pd/La_(1-x)Pb_xMnO_3 (x=0.2-0.7)

The magnetic perovskite-supported palladium catalysts Pd/Lal_xPbxMnO3 （x = 0.2-0.7） were prepared and used for the oxidative carbonylation of phenol to diphenyl carbonate. The synthesized catalysts were characterized by the X-ray diffraction （XRD）, surface area measurement BET, vibration sample magnetometer （VSM） and tem- perature-programmed reduction （TPR）. The experimental results demonstrated that the magnetic Pd/La1-xPbxMnO3 （x = 0.4-0.5） obtain relative better catalytic activity. It can be explained by higher concentration of oxygen vacan- cies, larger amount and better mobility of lattice oxygen of their support. Furthermore, these samples possess suffi- cient saturated magnetization. Thus, Pd/La1-xPbxMnO3 （x = 0.4-0.5） may be suitable for operation in the magneti- cally stabilized bed reactor.

An efficient catalytic system for the synthesis of glycerol carbonate by oxidative carbonylation of glycerol

Glycerol carbonate was synthesized by the oxidative carbonylation of glycerol catalyzed by the commercial Pd/C with the aid of NaI. High conversion of glycerol （82.2%）, selectivity to glycerol carbonate （〉99%）, and TOF （900 h-1） were obtained under the conditions of 5 MPa （Pco：Po2 = 2：1）, 140 C, 2 h. The highly active palladium species were generated in situ by dissolution from the carbon support and stabilized by re-deposition onto the support surface after the reaction was finished. Palladium dissolution and re-deposition were crucial and inherent parts of the catalytic cycle, which involved heterogeneous reactions. This Pd/C catalyst could be recycled and efficiently reused for four times with a gradual decrease in activity. Moreover, the in- fluences of various parameters, e.g., types of catalysts, solvents, additives, reaction temperature, pressure, and time on the conversion of glycerol were investigated. A reaction mechanism was proposed for oxidative carbonylation of glycerol to glyc- erol carbonate.