摘要
利用超声辅助溶胶-凝胶法,以钛酸正丁酯为钛源,制备了TiO 2负载于活化半焦的光催化剂.考察了TiO 2负载量,煅烧温度和时间,以及水对光催化脱硝活性的影响.利用X射线衍射(XRD),BET,FT-IR,扫描电镜(SEM)以及能谱分析(EDS)等方法对催化剂进行了表征分析.实验结果表明,TiO 2负载量为5.22%,煅烧温度500℃,煅烧时间为1 h时,TiO 2/ASC光催化脱硝剂效果最好,反应3 h后脱硝率仍高于70%.通过添加自由基捕获剂的方法确定TiO 2/ASC光催化脱硝过程中起主要作用的活性物种为·OH和·O-2,而空穴在本实验的光催化过程中几乎不起作用.对催化剂的再生研究发现,高温(400℃)水热一次再生可恢复催化剂脱硝活性至新鲜催化剂的100%,3次再生效果仍为新鲜催化剂脱硝率的80%.
TiO2 supported on activated semi-coke( ASC) is prepared by the ultrasonic assisted sol-gel method,tetra-n-butyl titanate as precursor. The effects of TiO 2loading amount,calcination temperature and time,and water vapor on the activity of photocatalytic oxidation of NO have been investigated. Prepared photocatalysts are characterized by X-ray diffraction(XRD),FT-IR,scanning electron microscopy(SEM) and energy dispersive spectrometer(EDS). With the optimum TiO2 load,5. 22%,calcinated at 500 ℃ for 1 h,TiO 2/ ASC photocatalyst performs the best photocatalytic activity with more than70% NO conversion after a 3-hour reaction. Results indicate that the hydroxyl radical,·OH,and superoxide radical,·O-2,are responsible for NO photocatalytic oxidation while photodenerated hole has little effect in photocatalytic reaction.Regeneration test results show that the photocatalysts perform high stability and high-temperature with vapor in is an optimum regeneration method.
出处
《分子催化》
EI
CAS
CSCD
北大核心
2015年第2期188-196,共9页
Journal of Molecular Catalysis(China)
基金
Supported by the National Science&Technology Pillar Program during the 12th Five-year Plan Period(2011BAD14B04)
