物理化学学报2013，Vol.29Issue(7)：1550-1557,8.DOI:10.3866/PKU.WHXB201304283
NH3-SCR反应过程中NH3和NOx在Cu/SAPO-34分子筛催化剂上的吸附特性和作用
Properties and Roles of Adsorbed NH3 and NOx over CulSAPO-34 Zeolite Catalyst in NH3-SCR Process
摘要
Abstract
To investigate the adsorption properties and roles of different feed gases in the selective catalytic reduction by ammonia (NH3-SCR),the adsorption sites,strength,and amount as well as reaction rates of NH3 and NOx (a mixture of NO and NO2) on exchanged Cu/SAPO-34 (chabazite zeolite) catalyst were studied.Transient response,temperature programmed desorption (TPD),and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) experiments were performed to characterize the catalyst.Transient response experiments showed that NH3 was adsorbed by the catalyst.TPD and DRIFTS indicated that NH3 can be adsorbed at both Brφnsted and Lewis acid sites to form various NH3 adsorption species that show different SCR activities.The adsorption rate of NH3 by Cu2+ cations was the fastest and the adsorption bond strength of NH3-Cu2+ was the strongest between NH3 and the Cu/SAPO-34 catalyst.NOx can be oxidized and stored as nitrates and nitrites on the Cu catalyst.The intermediate species formed at Cu active sites during the NH3-SCR reaction are discussed,allowing SCR reaction mechanisms to be inferred.关键词
NH3选择性催化还原/NOx(NO和NO2)/Cu/SAPO-34/漫反射傅里叶变换红外光谱/吸附物种Key words
Ammonia selective catalytic reduction/ NOx (NO and NO2)/ Cu/SAPO-34/ Diffuse reflectance infrared Fourier transform spectrum/ Adsorption species分类
化学化工引用本文复制引用
石琳,于铁,王欣全,王军,沈美庆..NH3-SCR反应过程中NH3和NOx在Cu/SAPO-34分子筛催化剂上的吸附特性和作用[J].物理化学学报,2013,29(7):1550-1557,8.基金项目
The project was supported by the National High-Tech Research and Development Program of China (863) (2011AA03A405).国家高技术研究发展计划项目(863) (2011AA03A405)资助 （863）
