Insight into the catalytic performance and NH3 adsorption under high concentration of CO2 and/or H2O conditions on selective catalytic reduction of NO by NH3 over V2O5-WO3/TiO2 catalyst
Insight into the catalytic performance and NH3 adsorption under high concentration of CO2 and/or H2O conditions on selective catalytic reduction of NO by NH3 over V2O5-WO3/TiO2 catalyst
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DOI：
10.1016/j.fuel.2020.119478
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发表时间：
2021-02
期刊：
影响因子：
7.4
通讯作者：
Mengxia Qing;Sheng Su;Kun Qian;Liang Liu;Yin Zijun;Song Hu;Yi Wang;J. Xiang
中科院分区：
文献类型：
--
作者：
Mengxia Qing;Sheng Su;Kun Qian;Liang Liu;Yin Zijun;Song Hu;Yi Wang;J. Xiang
在不同的燃烧过程中，烟气中都会同时存在CO_2和H_2O，了解高浓度CO_2和H_2O对V_2O_5-WO_3/TiO_2催化剂的影响机理可以为实现超低排放提供必要的信息。本研究主要考察了V2O5-WO_3/TiO_2催化剂在高浓度CO_2和H_2O条件下对NH3的吸附和催化性能。用X射线衍射仪、NH3-TPD、XPS和DRIFTS等分析手段对催化剂的性能进行了表征。结果表明，NO与NH3的反应遵循E-R机理，CO2和H2O主要通过影响O-α的比例、V4+的比例和NH3的吸附比例来影响NO的转化率，但不会改变催化剂的物理结构和晶体结构。在CO2和H2O条件下，NH3在催化剂上的吸附是复杂的。CO2对NH3吸附的净影响可以忽略不计，H2O对NH3吸附有普遍的抑制作用。尽管添加25%的H2O通过形成羟基增加了催化剂上O-α的比例，但V4+比例的降低和NH3的吸附在脱除NO过程中起主导作用，导致含H2O气氛下的NO转化率显著降低。
Under various combustion process, CO2and H2O both would exist in flue gas, the understanding of the influence mechanism of high concentration of CO2and H2O on V2O5-WO3/TiO2catalysts can provide needed information for the achievement of ultra-low emission. This study predominantly investigated NH3adsorption and catalytic performance of V2O5-WO3/TiO2catalyst under high concentration of CO2and H2O conditions. Analyses of XRD, NH3-TPD, XPS and DRIFTS were performed to characterize the catalyst properties. Results show that the reaction between NO and NH3followed E-R mechanism, CO2and H2O mainly affect NO conversion by influencing the proportion of Oα, proportion of V4+and NH3adsorption, which would hardly change the physical and crystalline structure of the catalyst. NH3adsorption on catalysts is complicated under CO2and H2O conditions. The net effect of CO2on NH3adsorption was negligible, and H2O inhibited NH3adsorption generally. Although the addition of 25%H2O increased the proportion of Oα on catalyst by forming hydroxy groups, the decreasing of V4+proportion and NH3adsorption play dominant roles in NO removal process, resulting in the significantly decrease of NO conversion under H2O-containing atmospheres.