闫东杰,李亚静,郭通,陈兆辉,玉亚,潘永宝.Mn-Ce/TiO2低温SCR催化剂成型过程添加剂的影响[J].环境科学学报,2021,41(2):423-429
Mn-Ce/TiO2低温SCR催化剂成型过程添加剂的影响
- Effect of additives on Mn-Ce/TiO2 low temperature SCR catalyst in the molding process
- 基金项目：陕西省重点研发计划项目（No.2020SF-432）；陕西省自然科学基础研究计划项目（No.2016JQ5095）
- 闫东杰
- 西安建筑科技大学环境与市政工程学院, 陕西省环境工程重点实验室, 西安 710055
- 李亚静
- 西安建筑科技大学环境与市政工程学院, 陕西省环境工程重点实验室, 西安 710055
- 郭通
- 西安建筑科技大学环境与市政工程学院, 陕西省环境工程重点实验室, 西安 710055
- 陈兆辉
- 西安建筑科技大学环境与市政工程学院, 陕西省环境工程重点实验室, 西安 710055
- 玉亚
- 西安建筑科技大学环境与市政工程学院, 陕西省环境工程重点实验室, 西安 710055
- 潘永宝
- 陕西现代建筑设计研究院, 西安 710048
- 摘要：催化剂成型过程中添加剂的种类和添加量对成型后催化剂的机械强度、成型效果和催化性能有很大影响.本文研究了Mn-Ce/TiO2催化剂制备过程中添加剂对催化剂的低温脱硝性能和机械性能的影响.结果表明，添加10%的拟薄水铝石作为黏结剂，可使催化剂具有较强的机械强度；添加2.5%的活性炭作为造孔剂，可以有效改善催化剂的孔结构.催化剂成型后脱硝性能下降，反应温度为90℃和120℃时，催化剂的NOx转化率分别下降了15%和30%左右，当温度到达150℃及以上时，催化剂成型前后的脱硝性能基本一致.最后，通过BET、FT-IR、NH3-TPD和H2-TPR表征分析原因：成型后催化剂比表面积和孔容下降，催化剂的表面酸性位点和氧化还原能力下降都会影响催化剂的脱硝性能，所以催化剂成型后低温活性变差.
- Abstract：The mechanical strength, molding effect and catalytic activity of the Mn-Ce/TiO2-containing catalyst were seriously affected by the type and dosage of additives. In this paper, the effects of additives, pseudo-boehmite, on the low-temperature de-nitration activity and mechanical properties of Mn-Ce/TiO2 catalyst were evaluated in detail, that 10% (W/W) addition of pseudo-boehmite exhibited optimal mechanical strength. Moreover, activated carbon, worked as the pore-forming agent, obviously improved the pore structure of the catalyst with the dosage of 2.5%. After the catalyst which consisted of Mn-Ce/TiO2, activated carbon and pseudo-boehmite was formed, the de-nitration activity was decreased than that of Mn-Ce/TiO2 catalyst. About 15% and 30% decrease of NOx removal efficiency was revealed at the temperature of 90 ℃ and 120 ℃, respectively. In addition, it was further observed that the de-nitration performance of the catalyst before and after molding was increased and almost the same if the temperature was further increased and higher than 150 ℃. On the basis of characterization, the decrease of specific surface area and pore volume of the catalyst was observed after molding. Considering the importance of the surface acidic active sites and the reduction of the redox capacity of the catalyst on the de-nitration performance, the poor activity of catalysts at lower temperature is explainable.
