光催化降解气相甲苯反应特性的一种新预测模型

以TiO2(P25)为催化剂,研究了玻璃平板反应器在室内典型冬季工况紫外光催化降解甲苯的特性。甲苯的初试浓度为0～14mg/m3。实验发现,随着浓度的增大,甲苯的降解速率先增加,在达到一个最大值后急剧减小。一个考虑了催化剂钝化的动力学模型能很好的解释这种现象。文章提出了钝化区、最大反应速率、抑止浓度等概念,对光催化型净化器的设计与选用有非常重要的指导意义。

A New Kinetic Model for Predicting the Rate of Ultraviolet Photocatalytic Oxidation of Toluene in the Gas-phase

A glass-plate reactor coated with Degussa TiO2 (P25) was used to investigate the performance of ultraviolet photocatalytic oxidation (UV-PCO) of toluene at typical ambient temperature and moisture of winter. The concentration of toluene at reactor inlet ranged from 0 to 14mg/m3. Under these conditions,the degradation rate of toluene was rising with the concentration increasing at first,but began to decline when it reached a maximum value. To describe this issue,a new kinetic model that fit well with the experimental results was proposed. Considering the possibility of photoactivity decay,it could approach to a good interpretation for the new model. Besides,the concepts of deactivation region,maximum rate and inhibiting concentration were proposed to explain the testing phenomena. Results would be useful for designing an appropriate UV-PCO air purifier.