环境污染治理技术及原理
蔡铁军,吕晓萌,邓谦,肖菡曦,彭振山.复合催化剂PWn/TiO2光催化降解甲醛反应的研究[J].环境科学学报,2005,25(5):618-622
复合催化剂PWn/TiO2光催化降解甲醛反应的研究
- Study on the photodegradation of formaldehyde with PWn/TiO2 composite catalysts
- 基金项目：湖南省科技厅自然科学基金科研项目(04JJ6003);湖南省教育厅科研项目(03C553)
- 作者
- 单位
- 蔡铁军
- 湖南科技大学化学化工学院, 湘潭 411201
- 吕晓萌
- 湖南科技大学化学化工学院, 湘潭 411201
- 邓谦
- 湖南科技大学化学化工学院, 湘潭 411201
- 肖菡曦
- 湖南科技大学化学化工学院, 湘潭 411201
- 彭振山
- 湖南科技大学化学化工学院, 湘潭 411201
- 摘要：合成了PWn/TiO2(n=11,12)两种复合催化剂,运用FTIR,TG-DTA,BET比表面积,SEM,FL等手段对复合催化剂进行了表征,并将其用于甲醛的光催化氧化降解实验结果表明,PW11/TiO2复合催化剂中的钛醇基团可在PW11的缺位位置发生化学键合作用,导致复合体系中结构的变化,光催化活性较低;PW12/TiO2复合催化体系中不仅保持了PW12完整的Keggin结构,而且,经30℃焙烧处理后PW12与TiO2形成载流子的有效迁移,使得复合催化剂具有较高的光催化活性,明显优于纯TiO2.2种复合催化剂对甲醛的光催化降解反应遵循L-H机理,符合一级动力学方程PW12/TiO2(30℃焙烧)和PW11/TiO2(300℃焙烧)为催化剂时,光催化降解的表观反应速率常数分别为0.01243 min-1,0.00214 min-1.
- Abstract：PWn/TiO2 composite catalysts were prepared by the method of sol-gel via calcination technique. Structure characterization was obtained by TG-DTA,FTIR,BETspecific surface area, TPR, SEM, FL. Photocatalytic performance of composite catalysts was investigated with formaldehyde as test compound in a static photoreactor made of quartz glass.The results showed that PW12/TiO2 composite catalyst(calcinated at 350℃)kept complete Keggin structure, and the carriers effectively transferred from TiO2 to PW12, so PW12/TiO2 composite catalysts had better photocatalysis activity than pure TiO2 and that ≡Ti-OH may combine with PW11 at its lacunary position, leading to structure change, so PW11/TiO2 composite catalysts had lower photocatalysis activity than PW12/TiO2. Photocatalysis reactions over two type composite catalysts accorded to L-Hmechanism , which had first order kinetic equation. First-order reaction rate constant of PW12/TiO2 and PW11/TiO2 were 0.01243min-1 and 0.005214min-1.
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