不同方式合成纳米TiO2载体在SCR脱硝催化剂制备中的应用

通过不同方式合成纳米TiO2,并以此为载体负载活性物质制得1%V2O5-10%WO3/TiO2的SCR脱硝催化剂.纳米TiO2制备方式包括溶胶凝胶法、TiCl4水解法、直接沉淀及均相沉淀法.试验结果表明,用这4种方法制备得到的TiO2均为锐钛型,以均相沉淀法合成的纳米TiO2为载体制得的催化剂具有较高的比表面积及脱硝性能,并表现出明显的活性温度窗口.进一步引入超声作用优化均相沉淀反应条件,结果表明,相比同类型传统方法,超声均相沉淀工艺能够明显提高纳米TiO2产品的比表面积与分散度,缩小二次颗粒尺寸,并使得所制备催化剂脱硝性能得到显著提高,且具有较好的抗水、抗硫特性.

Nano-TiO2 preparaed from different ways and application in SCR DeNOx catalyst

Nano-TiO2 materials were prepared from different ways,which were then used as carriers for preparation of SCR(selective catalytic reduction) DeNOx catalyst by incipient impregnation.Those catalysts were composed of 1%V2O5-10%WO3/TiO2 uniformly.The choosed synthesization ways for nano-TiO2 preparation included sol-gel method,hydrolysis of TiCl4,direct precipitation and homogeneous precipitation.Analysis results show that TiO2 from these 4 methods are all anatase-TiO2,among which the TiO2 and catalyst samples prepared from homogeneous precipitation exhibit relatively higher BET(Brunauer Emmett Teller) specific surface area and DeNOx catalytic activity,and the catalyst shows a stable activity temperature window.Furthermore,ultrasonic treatment was introduced into homogeneous precipitation to optimize reaction condition.And the results show that compared with conventional method,the ultrasound process can significantly improve BET specific surface area and dispersion of resultant TiO2,and reduce the diameter of second particle.Accordingly the activity of SCR DeNOx catalyst can be enhanced obviously with high antitoxic property for SO2 and H2O.