WO_3负载的金属催化剂催化性能研究

通过共沉淀法制备了一系列WO3负载的金属催化剂,以甲醇低温裂解、苯加氢和甲苯加氢为探针反应,考察了其催化性能。实验发现对甲醇低温裂解反应,WO3负载的金属催化剂没有提高金属催化剂的催化活性,载体WO3对甲醇低温裂解反应没有促进作用;而对苯和甲苯加氢反应,WO3负载的金属催化剂的活性却大大提高,载体WO3对苯和甲苯发生加氢反应有明显的促进作用。这是由于吸附在不饱和W中心上的苯和甲苯,与金属活性中心活化的溢流氢发生反应,分别生成环己烷和甲基环己烷。

WO_3负载量对V_2O_5/WO_3-TiO_2催化剂脱硝性能的影响

采用V_2O_5/WO_3-TiO_2作为脱硝催化剂,考察活性组分V_2O_5和助剂WO_3负载量对催化剂脱硝活性和抗硫抗水性能的影响。结果表明,3%V_2O_5/x WO_3-TiO_2催化剂(x=3%、4%、5%、6%、7%、8%、9%、10%)上NOx转化率随着WO_3负载量增加而升高,催化剂反应温度窗口不断拓宽。单独通水蒸汽及同时通SO2和水蒸汽对催化剂的毒害作用均较强,表明H2O和NH3的竞争吸附是催化剂抗硫抗水性能较差的重要原因。SO_2与H_2O和NH_3反应生成亚硫酸铵盐和硫酸铵盐,导致催化剂孔隙堵塞,催化活性降低。

V2O5/WO3-TiO2催化剂对NO转化率和N2O生成量的影响

采用V2O5/WO3-TiO2作为脱硝催化剂,考察不同厂家载体,活性组分V2O5和助剂WO3负载量对催化剂脱硝活性的影响。结果表明,不同厂家载体对催化剂低温活性影响较大,高温时影响不大;1.5V2O5/xWO3-TiO2(x=6%,10%,15%)上NO转化率随着WO3含量增加而升高,同时N2O也随着WO3含量增加而升高。

Preparation, characterization and photocatalytic behavior of WO_3-TiO_2/Nb_2O_5 catalysts

TiO2/Nb2O5 photocatalyst loaded with WO3 （WO3-TiO2/Nb2O5） was prepared by a modified hydrolysis process, and characterized by X-ray diffractometry, transmission electron microscopy, Raman spectra and UV-Vis diffuse refraction spectroscopy. The photocatalytic activity of WO3-TiO2/Nb2O5 was investigated by employing splitting of water for O2 evolution. The results indicate that WO3 loading can pronouncedly improve the photocatalytic activity of TiOjNb2O5 by using Fe^3＋ as an electron acceptor under UV irradiation. The optimum molar fraction of the loaded WO3 is 2%, and the largest speed of O2 evolution for 2% WO3-TiO2/Nb2O5 catalyst is 151.8 μmol/（L·h）.

Effect of WO3 Nanoparticle Loading on the Microstructural, Mechanical and Corrosion Resistance of Zn Matrix/TiO2-WO3 Nanocomposite Coatings for Marine Application

In this study, for marine application purposes, we evaluated the effect of process parameter and particle loading on the microstructure, mechanical reinforcement and corrosion resistance properties of a Zn-TiO2-WO3 nanocomposite produced via electrodeposition. We characterized the morphological properties of the composite coatings with a Scanning Electron Microscope （SEM） equipped with an Energy Dispersive Spectrometer （EDS）. We carried out mechanical examination using a Dura Scan hardness tester and a CERT UMT-2 multi-functional tribological tester. We evaluated the corrosion properties by linear polarization in 3.5% NaCl. The results show that the coatings exhibited good stability and the quantitative particle loading greatly enhanced the structural and morphological properties, hardness behavior and corrosion resistance of the coatings. We observed the precipitation of this alloy on steel is greatly influenced by the composite characteristics.