Mechanism-based kinetic modeling of Cu-SSZ-13 sulfation and desulfation for NH3-SCR applications

被引:32
|
作者
Jangjou, Yasser [1 ]
Sampara, Chaitanya S. [1 ]
Gu, Yuntao [1 ]
Wang, Di [2 ]
Kumar, Ashok [2 ]
Li, Junhui [2 ]
Epling, William S. [1 ]
机构
[1] Univ Virginia, Dept Chem Engn, Charlottesville, VA 22904 USA
[2] Cummins Inc, Catalyst Technol, Columbus, IN USA
关键词
SELECTIVE CATALYTIC-REDUCTION; NH3; OXIDATION; SO2; SCR; NOX; CU/SSZ-13; SULFUR; IMPACT; DEACTIVATION; AMMONIA;
D O I
10.1039/c8re00210j
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
A multi-site kinetic model was developed to predict the effect of sulfur dioxide on Cu-SSZ-13 for the NH3 selective catalytic reduction (NH3-SCR) of NOx. To develop a mechanism-based kinetic model, two different Cu sites were assumed describing the formation-decomposition of S intermediates i. e. copper bisulfite on ZCuOH (site 1, S1) and ammonium sulfate on Z(2)Cu (site 2, S2). Transient kinetics of SO2 interactions with Cu-SSZ-13 were simulated, exploiting SO2 and SO2 + NH3 temperature programmed desorption (TPD) experiments. Besides S1 and S2, a 3rd site was assumed to account for the Bronsted acid site and NH3 adsorption on that site. The model also accounts for NH3-SCR activity over fresh, sulfated and regenerated (at 550 degrees C) Cu-SSZ-13 samples with different Si : Al and Cu : Al ratios. Finally, the model was capable of describing fresh SCR for commercial and prepared samples without tuning any kinetic parameters, but by only varying ZCuOH and ZCu site densities obtained utilizing H-2 temperature programmed reduction (H2TPR) and inductively coupled plasma optical emission spectroscopy (ICP-OES).
引用
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页码:1038 / 1049
页数:12
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