Kinetic analysis of photocatalytic oxidation of gas-phase formaldehyde over titanium dioxide.
Kinetic analysis of photocatalytic oxidation of gas-phase formaldehyde over titanium dioxide.
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DOI：
10.1016/j.chemosphere.2005.01.039
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发表时间：
2005-07
期刊：
影响因子：
8.8
通讯作者：
Hongmin Liu;Z. Lian;Xiaojiang Ye;W. Shangguan
中科院分区：
文献类型：
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作者：
Hongmin Liu;Z. Lian;Xiaojiang Ye;W. Shangguan
在光催化反应器中对不同初始浓度的甲醛在二氧化钛上进行了降解实验。光催化速率符合简化的朗缪尔-辛舍伍德模型。动力学分析表明，与高浓度甲醛相比，低浓度甲醛的表观一级反应系数低，光催化半衰期长。建立了光催化产物的网络形成模型。实验结果和分析表明，在光照前催化剂上存在大量预吸附甲醛的情况下，气相中的二氧化碳浓度和一氧化碳浓度随光照时间呈指数变化，甚至可能高于气相中的甲醛浓度。甲醛光氧化过程中产生的副产物之一是一氧化碳。
Degradation of formaldehyde with different initial concentration over titanium dioxide was carried out in a photocatalytic reactor. Photocatalytic rates were well described by the simplified Langmuir–Hinshelwood model. The kinetic analysis shows that the apparent first-order reaction coefficient is lower and half-life of photocatalysis is longer for low concentration than for high concentration formaldehyde. A network formation model of the photocatalytic products was established. Experimental results and analysis demonstrate that carbon dioxide concentration and carbon monoxide concentration in gas phase vary exponentially with the illumination time and may be even higher than gas-phase formaldehyde concentration if there is much pre-adsorbed formaldehyde in adsorption equilibrium on catalysts before illumination. Carbon monoxide is found to be one of the by-products during formaldehyde photooxidation.