摘要
选择性催化还原(SCR)技术是降低柴油机NO_(x)排放的常用技术,其核心部件为催化剂.目前最广泛使用的催化剂为V_(2)O_(5)/TiO_(2)催化剂,但其存在一些缺点,如低温活性不佳、活性温度窗口较窄等.为了解决该催化剂存在的上述一系列问题,我们对V_(2)O_(5)/TiO_(2)催化剂进行改性处理.采用溶胶-凝胶法和浸渍法制备了B改性的V_(2)O_(5)/TiO_(2)催化剂,在标准工况下,在催化剂活性测试平台上对B改性后的催化剂进行活性测试实验,采用XRD、BET和NH_(3)-TPD对催化剂结构进行表征.实验结果表明B改性能有效增大催化剂的比表面积和孔容,使催化剂表面弱酸量增加,进而表现出较高活性和稳定性.此外,研究了空速、氧气浓度、氨氮比以及SO_(2)和H_(2)O(g)对催化剂选择性催化还原NO_(x)的影响.结果表明,改性催化剂具有较好的抗硫、抗水中毒能力.
Selective Catalytic Reduction (SCR) technology is a common method to reduce NO_(x) emissions from diesel engines.The catalyst is the core component of the SCR process.The most widely used catalyst is V_(2)O_(5)/TiO_(2) catalyst,but it has some defects,such as poor low-temperature activity,narrow active temperature window,etc.In order to solve above-mentioned problems,a series of B-modified V_(2)O_(5)/TiO_(2) catalyst was prepared by the sol-gel and the impregnation methods.The activity test experiment of the B-modified catalyst was carried out on the catalyst activity test platform.The microstructure and acid site were investigated by XRD,BET and NH_(3)-TPD methods.The results showed that the B modification could increase the specific surface area and the pore volume of the catalyst,and enhance the weak acid sites,which might result in high activity and stability of the catalyst.In addition,the effects of space velocity,O_(2) concentration,NH_(3)/NO ratio,SO_(2) concentration and water vapor on the catalyst for selective catalytic reduction of NO_(x) by NH3 were studied.The results show that the catalyst has preferable applicability and strong sulfur tolerance and hydrothermal stability.
作者
李航航
赵炜
王谦
吴里程
LI Hang-hang;ZHAO Wei;WANG Qian;WU Li-cheng(School of Energy and Power Engineering,Jiangsu University,Zhenjiang,212013,China)
出处
《分子催化》
EI
CAS
CSCD
北大核心
2021年第2期121-129,共9页
Journal of Molecular Catalysis(China)
基金
国家自然科学基金(51506077)
江苏省自然科学基金(BK20150488)
江苏省高校自然科学基金(15KJB610003)
江苏大学高级人才基金(15JDG156)。
关键词
B改性
催化剂
选择性催化还原
SCR活性
脱硝率
boron-modified
catalyst
selective catalytic reduction
SCR activity
NO_(x)removal efficiency
