【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,PW1 1 TiO2 复合催化剂中的钛醇基团可在PW1 1 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;PW1 2 TiO2 复合催化体系中不仅保持了PW1 2 完整的Keggin结构,而且,经3 5 0℃焙烧处理后PW1 2 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.PW1 2 TiO2 (3 5 0℃焙烧)和PW1 1 TiO2 (3 0 0℃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 0 12 43min- 1 ,0 0 0 5 2 14min- 1 .更多还原

【Abstract】 PW_n/TiO₂ composite catalysts were prepared by the method of sol-gel via calcination technique. Structure characterization was obtained by TG-DTA,FTIR,BET specific 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-H mechanism , 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.更多还原