乙酸和烯烃催化直接合成乙酸酯的研究进展

评述了乙酸与烯烃直接合成乙酸酯的液体酸及其固载化类、硅铝氧化物和硅酸盐类、离子交换树脂类、杂多酸类催化剂的研究进展。从反应工艺方面综述了杂多酸气相法催化乙酸与烯烃合成乙酸酯的研究开发和工业应用状况 。

甲烷低温催化直接合成乙酸的新途径

对甲烷经合成气路线间接制乙酸的现状及在温和条件下直接转化制乙酸的研究进展作了述评，通过对间接与直接路线的比较，以及在直线路线中，甲烷低温氧化羰化和直接羧化制乙酸均相与非均相催化体系的分析，指出了CH4－CO2低温直接合成乙酸在工艺过程上的显著优势，尤其是采用非均相催化体系。该工艺为乙酸合成和CH4与CO2的绿色化学利用开辟了新途径，其研究将会丰富C1化学化工的理论与实践，并为实现热力学不利反应提供实验方法和理论依据。

γ-丁内酯直接脱水催化法合成NVP工艺研究

以γ-丁内酯和乙醇胺为原料,直接脱水催化方法制备出N-乙烯基吡咯烷酮。主要探讨工艺及最佳工艺参数。

电位滴定法测定间羟基苯甲醛合成中残留的间甲酚

采用直接电位滴定法配合亚硫酸氢钠加成法测定间羟基苯甲醛合成中残留间甲酚的含量 ,平行测定结果误差不大于 0 .2 % ,平均偏差在 0 .1%以下 ,方法简便易行 。

The relationship between the microstructures and catalytic behaviors of iron–oxygen precursors during direct coal liquefaction

A series of both unsupported and coal‐supported iron–oxygen compounds with gradual changes in microstructure were synthesized by a precipitation‐oxidation process at 20 to 70°C.The relationship between the microstructures and catalytic activities of these precursors during direct coal liquefaction was studied.The results show that the microstructure could be controlled through adjusting the synthesis temperature during the precipitation‐oxidation procedure,and that compounds synthesized at lower temperatures exhibit higher catalytic activity.As a result of their higher proportions ofγ‐FeOOH orα‐FeOOH crystalline phases,the unsupported iron–oxygen compounds synthesized at 20–30°C,which also had high specific surface areas and moisture levels,generate oil yields 4.5%–4.6%higher than those obtained with precursors synthesized at 70°C.It was also determined that higher oil yields were obtained when the catalytically‐active phase formed by the precursors during liquefaction(pyrrhotite,Fe1-xS)had smaller crystallites.Feed coal added as a carrier was found to efficiently disperse the active precursors,which in turn significantly improved the catalytic activity during coal liquefaction.

A Bi-component Cu Catalyst for the Direct Synthesis of Methylchlorosilane from Silicon and Methyl Chloride

A bi-component catalyst comprising CuC1 and metallic copper was used in the direct synthesis of me- thylchlorosilane to study the catalytic synergy between the different copper sources. The catalyst exhibited high ac- tivity and high selectivity of dimethyldichlorosilane （M2） in the stirred bed reactor. The effect of the proportion of CuC1 used was studied and 10%-30% CuC1 gave the best yield of M2. The use of CuC1 decreased the induction pe- riod of reaction, improved the selectivity in the induction stage, and gave a longer stable stage. These results sug- gest that bi-comoonent catalyst has advantazes in the direct synthesis reaction.

Pd catalysts supported on rGO-TiO_2 composites for direct synthesis of H_2O_2: Modification of Pd^(2+)/Pd^0 ratio and hydrophilic property

The use of nanostructured composites as catalyst supports is a promising route to prepare catalysts with high selectivity and productivity. In this work, reduced graphene oxide-TiO_2(rGP-x) composites with a variation of reduced graphene oxide(rGO) content were synthesized by hydrothermal method. Pd/rGP-x catalysts were prepared in incipient-wetness impregnation method for the direct synthesis of H_2O_2 from H2 and O_2. The morphology and electronic properties of catalysts were investigated by XPS, TEM, and Raman spectroscopy.The ratio of Pd^(2+)/Pd^0 and the hydrophobicity of the catalysts were increased with the rising content of rGO. As the amount of rGO in the catalysts varied in the range of 0.025 wt%–2 wt%, the selectivity of H_2O_2 exhibited a tendency of increasing firstly and then decreasing from 0.1 wt% to 2 wt%. It indicates that good catalytic performance for H_2O_2 synthesis can be achieved only when appropriate amount of rGO is introduced. The H_2O_2 selectivity and productivity of Pd/r GP-0.025 both improved remarkably compared with Pd/P25. This enhancement originated from the combined effects of the proper ratio of Pd^(2+)/Pd^0 and hydrophobicity of the catalyst.

Atomically dispersed Au_1 catalyst towards efficient electrochemical synthesis of ammonia

Tremendous efforts have been devoted to explore energy-efficient strategies of ammonia synthesis to replace Haber-Bosch process which accounts for 1.4% of the annual energy consumption. In this study, atomically dispersed Au_1 catalyst is synthesized and applied in electrochemical synthesis of ammonia under ambient conditions. A high NH＋4 Faradaic efficiency of 11.1 % achieved by our Au_1 catalyst surpasses most of reported catalysts under comparable conditions. Benefiting from efficient atom utilization, an NH＋4 yield rate of 1,305 μg h-1 mg-1Au has been reached, which is roughly 22.5 times as high as that by sup- ported Au nanoparticles. We also demonstrate that by employing our Au_1 catalyst, NH＋4 can be electro- chemically produced directly from N_2 and H_2 with an energy utilization rate of 4.02 mmol kJ-1. Our study provides a possibility of replacing the Haber-Bosch process with environmentally benign and energy-efficient electrochemical strategies.

Direct synthesis of parallel doped N-MoP/N-CNT as highly active hydrogen evolution reaction catalyst

Doped phosphide is promising in earthabundant element based catalysts for hydrogen evolution reaction(HER). Here we employ ammonium hypophosphite(NH4H2PO2) to synthesize a novel parallel doped catalyst,nitrogen doped molybdenum phosphide nanoparticles(NPs)supported on nitrogen doped carbon nanotubes(N-MoP/N-CNTs). The NH4H2PO2 as a bifunctional agent severs as both phosphidation agent and nitrogen source, which makes the synthetic route simple and efficient. The as-obtained parallel doped N-MoP/N-CNTs show an overpotential of 103±5 mV at 10 mA cm-2, which is 140 mV lower than that of MoP NPs. The enhanced HER performance is attributed to the electronic effect by doped MoP and CNTs supports. This work provides a facile route to synthesize doped phosphides for the potential applications in hydrogen energy.