SiO_2负载钼催化剂的合成及其催化乙烯二聚、同系化和歧化的反应性能

从单核及双核二甲胺钼络合物出发,制备了SiO_2负载的钼催化剂。程序升温分解实验(TPDE)及红外测试表明,双核钼络合物与SiO_2作用生成双钼中心物种,此物种可催化乙烯的二聚反应。280℃活化后此双钼中心物种变成单钼中心物种,单钼物种只催化乙烯的同系化及歧化反应。     

A New Efficient Synthesis of p-Nitrocalix[4]arene

A new efficient synthesis of p-nitrocalix[4]arene from calix[4]arene by using nitrogen dioxide is described.The compound is an useful intermediates for the introduction of other functional groups to obtain N containing substituted calix[4]arene.The reaction mechanism is briefly discussed.     

Adsorption, diffusion and desorption of chlorine on and from rutile TiO2{110}: a theoretical investigation.

The adsorption, diffusion and desorption of chlorine on and from stoichiometric, reduced and partially reduced (defective) rutile TiO2{110} are investigated using ab initio density functional theory (DFT) calculations. Theoretical results are compared with experimental investigations, and microkinetic simulations based on DFT values are then used to verify the diffusion mechanisms assumed in the experimental investigations.     

流动注射化学发光法测定自来水中二氧化氯

在pH12．5的NaOH—KCl缓冲介质中，ClO2直接氧化Luminol能产生很强的化学发光，而且发光强度在一定的范围内与ClO2的浓度呈线性关系，据此建立了流动注射化学发光测定ClO2的新方法。探讨了最佳的发光条件，测定ClO2的线性范围为0．5—200μg／L，检出限为0．3μg／L。本法简便、怏速、灵敏，选择性和重复性较好，应用于自来水中剩余ClO2的测定，结果满意。     

Ru/Mn-Ce/TiO2催化剂催化湿式氧化丁二酸的反应活性和动力学研究

在二氧化钛载体中通过掺杂Ru，Mn，Ce制备了一系列用于催化湿式氧化的催化剂，利用XRD，TEM，BET等手段对催化剂进行了表征．在反应温度T=210～270℃，氧分压Po2=2．1MPa条件下，在间歇式高压反应釜中对丁二酸进行了降解实验．催化剂在反应中有很高的催化活性．催化剂在30min内对丁二酸降解的COD去除率为54．4～98．3％．Ru及Mn，Ce的氧化物对催化活性都有促进作用．建立了丁二酸催化湿式氧化的一级分段动力学模型．基于COD的一段及二段反应的活化能分别为43．74kJ／mol和54．28kJ／mol．     

碘离子选择电极在动力学分析中的应用 Ⅰ.催化电势动力学测锆法研究

本文报道采用碘离子选择电极,系统研究了锆于BO_3~--I~-反应中的定量催化特性,建立了催化电势动力学间接测痕量锆的方法。结果表明,本法专属性较高,55种阴、阳离子均不干扰测锆。     

Preparation and characterization of nitrogen-doped TiO2 photocatalyst in different acid environments

Nitrogen-doped TiO₂ powders were successfully prepared by a wet method, i.e., a micro-emulsion-hydrothermal method, in different acid environments. Several characterization techniques, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV-visible diffuse reflectance spectra, were combined to determine the crystal phase, concentration and chemical states of the nitrogen doped in TiO₂. The high photocatalytic activity of the nitrogen-doped TiO₂ was evaluated through the decomposition of rhodanmine B under visible light irradiation. It was suggested that the doped nitrogen formed oxynitride (NO) and produced impurity states at higher above the valence band of TiO₂. Therefore, the nitrogen doping could enhance the response of photocatalyst to the visible light and improve the photocatalytic activity because of the narrowing of band gap of TiO₂.     

锆氢化反应研究2.羰基化合物的选择性还原

本文对芳香醛和酮的锆氢化反应及水解产物进行了研究。产物经NMR证明为相应的醇。并以苯甲醛为代表,初步探讨了锆氢化反应的过程。还研究了含有其他官能团的苯甲醛对锆氢化反应选择性的影响,以及含有较大取代基酮类的锆氢化反应。     

Vibrational spectra and structure of zirconium and hafnium cyclopentadienyl hydrides

Raman and IR spectra (4000-50 cm^–1) of solid cyclopentadienyl zirconium and hafnium hydrides Cp₂MH₂, Cp₂MD₂, Cp₂Zr(H)X, and Cp₂Zr(D)X (Cp = ⁵-C₅H₅; M = Zr, Hf; X = Cl, Br) have been studied. The vibrational modes of MH groups, Cp-rings, and metal-ligand bonds are discussed and the band assignments are proposed. In the solid state, these complexes form polymers with linear hydride bridges of the M-H-M type. The force constants of the M-H and M-Cp bonds increase on going from Zr to Hf.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1604–1609, September, 1994.     

TiO2光催化反应及其在环境保护中的应用

本文简要介绍了TiO2光催化剂的作用机理，讨论了影响TiO2光催化效率的因素及解决途径，综述了光催化在环境保护中的最新应用。