Enhanced effect of water vapor on complete oxidation of formaldehyde in air with ozone over MnOx catalysts at room temperature.
Enhanced effect of water vapor on complete oxidation of formaldehyde in air with ozone over MnOx catalysts at room temperature.
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DOI：
10.1016/j.jhazmat.2012.09.009
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发表时间：
2012-11
影响因子：
13.6
通讯作者：
Dezhi Zhao;C. Shi;Xiao‐Song Li;Aimin Zhu;B. Jang
中科院分区：
文献类型：
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作者：
Dezhi Zhao;C. Shi;Xiao‐Song Li;Aimin Zhu;B. Jang
在室温下，研究了水蒸气对MnOx催化剂上臭氧催化氧化甲醛制CO2反应的增强作用及其反应稳定性。在干燥的空气流中，只有低于20%的甲醛可以被O3氧化成CO2。在潮湿空气中（RH≥55%），O3可将近100%的甲醛氧化为CO2，反应稳定性显著提高。同时，在原位漫反射红外傅里叶变换（DRIFT）光谱的OZCO的甲醛表明，无论是单齿和双齿碳酸盐物种的MnOx，在干流，随着时间的流（TOS）逐渐增加。然而，在潮湿流中，几乎没有观察到碳酸盐物质在催化剂上的积累。为了阐明MnOx催化剂的强化机理，比较了新鲜、O3和O3+H2O处理的MnOx催化剂上的甲醛表面反应和CO2吸附/脱附。
At room temperature, the enhanced effect of water vapor on ozone catalytic oxidation (OZCO) of formaldehyde to CO2over MnOxcatalysts and the reaction stability was reported. In a dry air stream, only below 20% of formaldehyde could be oxidized into CO2by O3. In humid air streams (RH≥55%), ∼100% of formaldehyde were oxidized into CO2by O3and the reaction stability was significantly enhanced. Meanwhile, in situ Diffuse Reflectance Infrared Fourier Transform (DRIFT) spectra of OZCO of HCHO demonstrate that the amount of both monodentate and bidentate carbonate species on MnOx, in the dry stream, increased gradually with time on stream (TOS). However, in the humid stream, almost no accumulation of carbonate species on the catalysts was observed. To clarify the enhanced mechanism, formaldehyde surface reactions and CO2adsorption/desorption on the fresh, O3and O3+H2O treated MnOxcatalysts were examined comparatively.