title: DFT insights into the adsorption of NH3-SCR related small gases in Mn-MOF-74.
abstract: Mn-MOF-74 has great potential to catalyze selective catalytic reduction (SCR) reaction with NH3being the reductant (NH3-SCR). However, the reaction mechanism, in particular the adsorptive properties of key reactive species in Mn-MOF-74, remains ambiguous. Besides, the effects of impurities such as H2O and SO2on the process need further investigation. In this paper, based on density functional theory (DFT) calculations, we studied the adsorption characteristics of six NH3-SCR related small gases, namely NH3, NO2, NO, O2, H2O and SO2. DFT results show that the Mn-MOF-74 structure can bind these molecules relatively strongly in the following order: NH3> NO2> NO > O2, allowing for subsequent NH3-SCR reaction. In addition, a possible pathway of NO conversion to NO2was calculated. Investigation on competitive adsorption of NH3and H2O, NH3and SO2reveals that both H2O and SO2are probable to replace NH3under certain conditions, indicating that the two impurity gases may affect the activity of the NH3-SCR reaction. Compared with H2O, SO2can displace NH3more easily and should not be neglected.
authors.affiliation: Key Laboratory for Green Chemical Technology of Ministry of Education, R&D Center for Petrochemical Technology, Tianjin University, Tianjin 300072, China. yfchen@tju.edu.cn and Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China.
authors.forename: Minhua
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Key Laboratory for Green Chemical Technology of Ministry of Education, R&D Center for Petrochemical Technology, Tianjin University, Tianjin 300072, China. yfchen@tju.edu.cn and Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China.
authors.forename: Xuewei
authors.initials: X
authors.lastname: Huang
authors.affiliation: Key Laboratory for Green Chemical Technology of Ministry of Education, R&D Center for Petrochemical Technology, Tianjin University, Tianjin 300072, China. yfchen@tju.edu.cn and Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China.
authors.forename: Yifei
authors.initials: Y
authors.lastname: Chen