摘要
针对锰钛选择性催化还原(SCR)脱硝催化材料运行失活问题,采用X射线衍射(XRD)、N_2吸附-脱附(BET)、程序升温还原(H_2-TPR)、程序升温脱附(NH_3-TPD)、X射线光电子能谱分析(XPS)等表征手段,以及催化活性评价装置,对比分析了使用前后SCR脱硝催化材料催化活性以及物化性质的差异,综合分析SCR催化材料的失活原因。结果表明,催化材料在200℃下运行100 h后脱硝效率由98%下降到50%,催化活性降低是多种因素共同作用的结果,其中结晶度提高、活性成分分散性降低、表面酸性位点数量减少导致催化材料无法吸附足够的NH_3去参与反应,是催化活性降低的主要原因;而活性成分MnO_x中Mn^(3+)含量下降,晶格氧所占比例增加,也在一定程度上促进了催化材料的失活。
This paper focused on the problem of inactivation of MnOx/TiO2 SCR DENOx catalytic materials. To investigate the difference of physical and chemical properties of SCR denitrification catalyst before and after use,XRD,BET,H2-TPR,NH3-TPD,XPS were employed. The catalytic activity of catalysts was studied on the SCR activity reactor. Results showed that the denitrification efficiency of the catalytic material decreased from 98% to 50% after 100 h at 200 ℃. The decrease in catalytic activity was the result of a combination of multiple factors. It was mainly because that the decreased of the specific surface area,with the increasing of crystallinity,the acid sites decreased sharply and the catalytic materials cannot adsorb enough NH3. While the content of Mn3＋ in the active component decreased and the proportion of lattice oxygen increased,also promoted the deactivation of the catalytic material.
作者
万业强
崔素萍
郭红霞
马晓宇
张艳昭
WAN Ye-qiang;CUI Su-ping;GUO Hong-xia;MA Xiao-yu;ZHANG Yan-zhao(College of Materials Science and Engineering,Beijing University of Technology,Beijing 100124,China)
出处
《人工晶体学报》
EI
CAS
CSCD
北大核心
2018年第5期1006-1011,共6页
Journal of Synthetic Crystals
基金
国家重点研发计划(2017YFB0310802)
关键词
MnOx/TiO2催化材料
低温选择性催化还原
催化材料失活
酸性位点
MnOx/TiO 2 catalytic material
low temperature selective catalytic reduction
deactivation of catalytic material
acid site
