摘要
以硝酸和尿素对活性炭进行表面改性,考察了活性炭表面性能对负载的铈基催化剂活性和抗硫性能的影响。采用N2吸附-脱附、X射线衍射(XRD)、XPS等技术对催化剂结构和性能进行了表征。结果表明,催化剂的活性与抗硫性能与其表面酸性,表面官能团的种类与数量有关。硝酸处理活性炭可增强其表面酸性,增强活性炭与CeO2之间的相互作用,提高催化剂上CeO2的分散性、表面吸附氧和Ce3+比例,从而显著提高催化剂的活性和抗硫性能。尿素处理活性炭显著提升了催化剂中含氧官能团和N-6碱性官能团的量,大量含氧官能团的存在增加了活性炭表面不稳定基团的量,而大量的N-6官能团则降低了表面酸性,二者的共同作用减弱了活性炭与CeO2之间的相互作用,使活性组分分散性,表面吸附氧和Ce3+比例降低,并最终导致了所负载的铈基催化剂活性和抗硫性能的下降。
The surface property of activated carbon is modified by nitric acid and urea.The effect of surface property of activated carbon on denitration and sulfur resistance performance of supported cerium based catalyst is studied.N2 adsorption-desorption,XRD and XPS technologies are used to characterize the structure and performance of catalysts.The results show that activity and sulfur resistance performance are related to surface acidity,the type and quantity of surface functional groups.After the activated carbon is pretreated with nitric acid,the surface acidity,interaction between activated carbon and CeO2 are improved.Accordingly,the dispersity of CeO2,the ratio of surface adsorbed oxygen and Ce3+are also increased,significantly enhancing de-NOx and anti-SO2 performance of catalysts.The amount of oxygen and N-6 basic functional groups are increased after treated by urea.A large amount of oxygen and N-6 functional groups lead to increase of unstable groups and surface acidity of activated carbon,respectively.The combination of the two factors weaken the interaction between activated carbon and CeO2,resulting in decline of CeO2 dispersity,Ce3+ratio and surface adsorbed oxygen.At last,activity and sulfur resistance performance of catalysts are descended.
作者
黄利华
华坚
HUANG Lihua;HUA Jian(Institute of Environment and Resource of Southwest University of Science and Technology,Mianyang 621010, China;National Engineering Research Center for Flue Gas Desulfurization, Chengdu 610065, China)
出处
《功能材料》
EI
CAS
CSCD
北大核心
2020年第12期12174-12179,共6页
Journal of Functional Materials
基金
四川省教育厅资助项目(17zd1145)。
关键词
表面性能
活性炭
铈基催化剂
脱硝性能
抗硫性能
surface property
activated carbon
cerium based catalyst
denitration
sulfur resistance performance
