Laboratory of Plasma Physical Chemistry, School of Physics and Optoelectronic Engineering & School of Chemistry, Dalian University of Technology, Dalian 116024, China.
J Hazard Mater. 2012 Nov 15;239-240:362-9. doi: 10.1016/j.jhazmat.2012.09.009. Epub 2012 Sep 12.
At room temperature, the enhanced effect of water vapor on ozone catalytic oxidation (OZCO) of formaldehyde to CO2 over MnOx catalysts and the reaction stability was reported. In a dry air stream, only below 20% of formaldehyde could be oxidized into CO2 by O3. In humid air streams (RH≥55%), ∼100% of formaldehyde were oxidized into CO2 by O3 and 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 CO2 adsorption/desorption on the fresh, O3 and O3+H2O treated MnOx catalysts were examined comparatively.
室温下，报道了水蒸气对 MnOx 催化剂上甲醛臭氧催化氧化（OZCO）生成 CO2 的增强作用及反应稳定性。在干燥的空气流中，O3 只能将低于 20%的甲醛氧化成 CO2。在相对湿度（RH≥55%）的空气流中，O3 可将几乎 100%的甲醛氧化成 CO2，且反应稳定性显著增强。同时，OZCO 过程中甲醛的原位漫反射红外傅里叶变换（DRIFT）谱表明，在干燥的空气流中，MnOx 上的单齿和双齿碳酸盐物种的量随着运行时间（TOS）的增加而逐渐增加。然而，在潮湿的空气流中，几乎观察不到催化剂上碳酸盐物种的积累。为了阐明增强机制，对新鲜 MnOx、O3 和 O3+H2O 处理的 MnOx 催化剂上的甲醛表面反应和 CO2 吸附/解吸进行了比较研究。
