溶胶-凝胶法制备掺杂型V_2O_5/TiO_2脱硝催化剂

Preparation of doped V_2O_5/TiO_2 DeNOx catalyst through sol-gel method

以十二胺表面活性剂为模板剂,钛酸四丁脂为无机母体源,采用溶胶-凝胶法制得稳定的TiO_2凝胶,经焙烧得到掺杂型V_2O_5/TiO_2脱硝催化剂粉末。分别用热重分析、X射线衍射、拉曼光谱和氮气吸附脱附法对催化剂进行了结构、比表面积和孔径的表征。在固定反应床,对氮氧化物的脱除活性进行了考察。结果表明,催化剂为锐钛矿,呈介孔结构,比表面积为118.5 m_2·g^(-1),孔径(6～8)nm。钒以V=O键形式单层分布于TiO_2中。催化活性评价结果表明,制备的催化剂在空速10 000 h^(_1)和温度(180～450)℃有较好的催化活性,空速对催化活性的影响主要在270℃以下。

V_2O_5-doped V_2O_5/TiO_2 DeNOx catalyst powder was prepared by sol-gel method followed by calcinations,using surfactant dodecylamine as the template and tetrabutyl titanate as the inorganic precursor. Thermal stability,structure,surface area and pore size of the catalyst were characterized by TG/ DTA,XRD,Raman spectroscopy and N_2 adsorption/desorption.Activity of the catalyst for DeNOx was tested in a fixed-bed reactor.The results showed that there existed anatase phase and mesopore structure in the as-prepared V_2O_5/TiO_2 powder,with BET surface area of 118.5 m^2·g^(-1) and pore size of (6-8) nm.Vanadium was well dispersed by V=0 bridge monolayer in the TiO_2 support.The catalyst exhibited high catalytic activity under temperature ranging from 180 ℃.to 450 ℃ and space velocity of 10 000 h^(-1).Space velocity had influence on the catalytic activity in lower temperature range (lower than 270 ℃).