水热法制备Ni/Nd2O3催化剂及其催化水合联氨制氢

采用水热合成法制备了Ni/Nd₂O₃催化剂，对其催化水合联氨制氢性能进行了考察，探讨了催化剂合成条件及催化体系中NaOH浓度对催化性能的影响，并采用XRD、XPS、TEM、TG对催化剂进行了分析表征。结果表明，当Ni/Nd=94∶6、水热条件为8h、120℃时，合成的Ni/Nd₂O₃催化剂在催化水合联氨制氢时表现出了最优的催化性能，其H₂选择性为95.9%。该催化剂中Ni的结晶度较高，Nd以Nd₂O₃的形式存在，具有促进颗粒分散、暴露活性位点、协助Ni、Nd电子转移等优点。与不加NaOH溶液的催化制氢体系相比，当NaOH的加入浓度为1.3mol/L时，催化剂催化水合联氨的制氢速率提高了约3.7倍。催化剂可维持良好的稳定性，循环使用5次后H₂选择性仍高达94.4%。     

水合肼下游农药研究综述

水合肼作为一种重要的精细化工中间体,广泛应用于合成农药、医药、发泡剂、引发剂、固化剂、聚合催化剂等.综述了水合肼在各种农药合成中的应用.主要介绍了以水合肼作为原料在合成除草剂、杀虫剂、杀菌剂上的最新应用以及合成路线的优化.     

以氰基乙醛为中间体合成吡唑类化合物

以乙腈、乙醇钠和CO气体为原料,高压反应得到3-羟基丙烯腈的钠盐,中和得到氰基乙醛的溶液。氰基乙醛的溶液直接和肼反应,得到5-氨基吡唑类化合物,收率68%～85%。反应原料廉价易得,具有很高的原子经济性,符合绿色化学的要求,具有潜在的应用前景。     

5-乙酰乙酰氨基苯并咪唑酮合成工艺研究

以5-硝基苯并咪唑酮为原料,采用水合肼还原制备5-氨基苯并咪唑酮(BI),反应条件温和,安全,环境友好。研究了溶剂对BI合成5-乙酰乙酰氨基苯并咪唑酮(AABI)的影响:在乙酸乙酯中,BI与双乙烯酮反应合成AABI,收率可达89.3%。     

对氯苯肼合成工艺研究

研究了对氯苯胺与水合肼在催化下合成对氯苯肼的工艺条件,较佳工艺条件为:对氯苯胺0.5mol,溶剂9mL,对氯苯胺与水合肼、催化剂的摩尔比1∶2.5∶0.3,反应温度110℃,反应时间5h,产品收率达92.2%。     

巴柳氮的合成改进

以对-硝基苯甲酰氯为起始原料,经缩合、还原、重氮化、偶合4步反应制得巴柳氮,总收率73. 9%。利用TLC ,IR ,1HNMR对产品进行了表征。     

FeCl_3/PVP胶体催化水合肼还原硝基苯

以聚乙烯吡咯烷酮(PVP)为保护剂,采用水热合成法制备了FeCl3/PVP胶体催化剂,通过XRD和TEM方法对催化剂的形貌与结构进行了表征;考察了催化剂的制备条件(水热时间、PVP与FeCl3的摩尔比)和反应条件(反应温度、水合肼用量和催化剂用量)对还原反应的影响。实验结果表明,在PVP与FeCl3摩尔比1∶40、100℃下水热2h制得的胶体稳定性好、分散度高,其胶粒呈70～90nm的棒状结构。该胶体催化剂在催化水合肼还原硝基苯的反应中表现出很高的催化活性,在反应温度80℃、反应时间80min、硝基苯用量4.89mmol、无水乙醇用量5mL、FeCl3/PVP胶体催化剂用量2.0mL(nFe=0.150 0mmol)、n(水合肼)∶n(硝基苯)=2.5的条件下,苯胺收率可达100%。     

Synthesis of 3,6-diaryl-1,4,5-thiadiazepines from substituted 2-thiocyano acetophenone and investigation of reaction mechanism

In this work, we have studied the reaction of substituted 2-thiocyanoacetophenone and hydrazine hydrate as a novel and simple pathway for the preparation of the substituted 1,4,5-thiodiazepine ring system. The mechanism of this reaction revealed that in the initial step condensation of hydrazine with carbonyl groups of substituted 2-thiocyanoacetophenons 2a–2f gives the corresponding substituted aromatic dithiocyano azide intermediates which in turn undergo cyclization to1,4,5-thiadiazepines in the presence of hydrazine. This cyclization is a novel method for the preparation of sulfide bond from the reaction of hydrazine and a dithiocyano intermediate. An account of the reaction mechanism is given.     

水合联氨的合成及应用

介绍了水合联氨的两种合成方法－尿素氧化法和次氯酸钠氨化法以及水合联氨在医药、农药、发泡剂、抗氧剂、火箭燃料、香料等精细化学品生产中的应用，对水合联氨的开发利用具有一定的参考意义。     

Tuning Surface Composition of Ni-Pt/CeO2 Catalyst for Hydrogen Generation from Hydrous Hydrazine DecompositionEI北大核心CSCD

Hydrous hydrazine (N2H4 center dot H2O) is a water-like liquid with a high hydrogen density (8%, mass fraction), relatively low cost, and satisfactory stability under ambient conditions. Owing to these favorable attributes, N2H4 center dot H2O has attracted considerable attention as a promising hydrogen carrier for on-board or portable applications. The synthesis of highly active and selective catalysts is a central issue in developing practical hydrous hydrazine-based hydrogen generation systems. The development of high-performance catalysts requires fundamental knowledge of the correlation between the surface composition of the catalyst and its catalytic performance. In the present work, a supported Ni-Pt/CeO2 bimetallic nanocatalyst was prepared by a one-pot co-reduction method, and its use for catalyzing hydrous hydrazine decomposition to generate hydrogen was reported. The surface composition of the Ni-Pt/CeO2 catalyst was regulated by heat treatments under different atmospheres, such as air, NH3, H-2, and CO and at different temperatures. It was found that changing the annealing conditions may result in altered Ni/Pt ratio at the catalyst surface, and as a consequence the catalytic performance can be tailored. When the molar Ni/Pt ratio at the catalyst surface was 0.8 similar to 1.14, the catalyst has been found to possess remarkable catalytic activity towards hydrous hydrazine decomposition. Additionally, it was found that incorporation of non-metallic N element on the catalyst surface may result in remarkably improved catalytic activity of NiPt/CeO2 towards hydrous hydrazine decomposition. This finding may open new avenues for the development of high-performance catalyst for promoting hydrogen generation from hydrous hydrazine.