Controlled synthesis of Cu-based SAPO-18/34 intergrowth zeolites for selective catalytic reduction of NOx by ammonia

Shoute Zhang; Shujun Ming; Lei Guo; Ce Bian; Ying Meng; Qian Liu; Yahao Dong; Jiajun Bi; Dan Li; Qin Wu; Kaiwei Qin; Zhen Chen; Lei Pang; Weiquan Cai; Tao Li

doi:10.1016/j.jhazmat.2021.125543

Controlled synthesis of Cu-based SAPO-18/34 intergrowth zeolites for selective catalytic reduction of NO_x by ammonia

J Hazard Mater. 2021 Jul 15:414:125543. doi: 10.1016/j.jhazmat.2021.125543. Epub 2021 Feb 26.

Authors

Shoute Zhang¹, Shujun Ming¹, Lei Guo¹, Ce Bian¹, Ying Meng¹, Qian Liu¹, Yahao Dong¹, Jiajun Bi¹, Dan Li¹, Qin Wu¹, Kaiwei Qin¹, Zhen Chen¹, Lei Pang², Weiquan Cai³, Tao Li⁴

Affiliations

¹ Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry, of Education, Hubei Key Laboratory of Material Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, PR China.
² DongFeng Trucks R&D Center, Zhushanhu Road No. 653, Wuhan 430056, PR China.
³ School of Chemistry and Chemical Engineering, Guangzhou University, 230 Wai Huan Xi Road, Guangzhou Higher Education Mega Center, Guangzhou 510006, China.
⁴ Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry, of Education, Hubei Key Laboratory of Material Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, PR China. Electronic address: taoli@hust.edu.cn.

PMID: 33677322
DOI: 10.1016/j.jhazmat.2021.125543

Abstract

Cu-based SAPO-18, SAPO-18/34 intergrowth and SAPO-34 zeolites were applied for the selective catalytic reduction of NO_x by ammonia (NH₃-SCR) catalysts. Comprehensive characterization results revealed that the SAPO-18/34 with higher amount and strength of acid sites could facilitate the generation of more isolated copper ions (Cu²⁺ and Cu⁺) and suppress the formation of CuO_x, which might account for the fact that intergrowth crystal structure of Cu-SAPO-18/34 exhibited higher fresh NH₃-SCR activity, more robust hydrothermal durability and better SO₂-resistance ability than that Cu-SAPO-18 and Cu-SAPO-34. In situ DRIFTS results provided the formation of reaction intermediates, such as -NH₂, NH₄⁺, NO₃^-, NO₂^-, etc. Eley-Rideal (E-R) and Langmuir-Hinshelwood (L-H) reaction mechanisms were both involved in Cu-based SAPO-18 and SAPO-18/34 intergrowth zeolites, but the L-H mechanism dominated the NH₃-SCR reaction, in addition, Cu-SAPO-34 only followed "L-H" mechanism.

Keywords: In-situ DRIFTS; NH(3)-SCR; SAPO-18/34 intergrowth.