锆掺杂对介孔二氧化钛催化性能的优化

Optimization of Catalytic Properties for Meso-Porous Titania by Doping Zirconium

摘要:

采用溶胶-凝胶法制备二氧化钛晶须及钛锆复合氧化物，研究锆掺杂对介孔二氧化钛催化性能的优化，采用X 射线衍射（XRD）仪、扫描电镜（SEM）、能谱（EDS）分析、以NH3为分子探针傅里叶红外（FT-IR）及N2物理吸附（BET法）等测试手段，分别考察锆掺杂对二氧化钛晶型、晶粒形貌、固体表面酸性、比表面积的影响。结果表明，锆掺杂可以稳定锐钛矿晶型，改变TiO2结晶形貌，增强二氧化钛固体酸性，增大介孔二氧化钛比表面积，从而优化介孔二氧化钛的催化性能。基于TiO2作为脱硝催化剂，以NH3为还原剂进行NO的选择性催化还原脱除，锆掺杂明显拓宽催化活性温度窗口，往高温区偏移50~100 ℃，最高催化活性提高26.9%。

Abstract:

A series of titania whiskers and Ti-Zr composite oxides were prepared by sol-gel method. Optimization of catalytic properties for meso-porous titania by doping zirconium was investigated. Effects of doping zirconium on crystal form, grain morphology, specific surface area and solid acidity of titania were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy disperse spectra (EDS), Fourier infrared spectroscopic analysis (FT-IR) with NH3 as atom probe and N2 physical adsorption (BET method). The results show that doping zirconium could prohibit crystal transformation from anatase to rutile, change the grain morphology, enhance the solid acidity and increase the specific surface area of titania. Consequently, the catalytic properties of titania were optimized. In the process of selective catalytic reduction of NO, with TiO2 as denitration catalyst and NH3 as reducing agent, doping zirconium widened the catalytic temperature range to high temperature by 50-100 ℃, and the biggest catalytic activity in the experimental temperature range was improved by 26.9%.