Zhang Shoute, Ming Shujun, Guo Lei, Bian Ce, Meng Ying, Liu Qian, Dong Yahao, Bi Jiajun, Li Dan, Wu Qin, Qin Kaiwei, Chen Zhen, Pang Lei, Cai Weiquan, Li Tao
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.
DongFeng Trucks R&D Center, Zhushanhu Road No. 653, Wuhan 430056, PR China.
J Hazard Mater. 2021 Jul 15;414:125543. doi: 10.1016/j.jhazmat.2021.125543. Epub 2021 Feb 26.
Cu-based SAPO-18, SAPO-18/34 intergrowth and SAPO-34 zeolites were applied for the selective catalytic reduction of NO by ammonia (NH-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 (Cu and Cu) and suppress the formation of CuO, which might account for the fact that intergrowth crystal structure of Cu-SAPO-18/34 exhibited higher fresh NH-SCR activity, more robust hydrothermal durability and better SO-resistance ability than that Cu-SAPO-18 and Cu-SAPO-34. In situ DRIFTS results provided the formation of reaction intermediates, such as -NH, NH, NO, NO, 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 NH-SCR reaction, in addition, Cu-SAPO-34 only followed "L-H" mechanism.
铜基SAPO - 18、SAPO - 18/34共生结构和SAPO - 34沸石被用作氨选择性催化还原NO（NH - SCR）催化剂。综合表征结果表明，具有较高酸量和酸强度的SAPO - 18/34能够促进更多孤立铜离子（Cu⁺和Cu²⁺）的生成，并抑制CuO的形成，这可能解释了Cu - SAPO - 18/34的共生晶体结构在新鲜NH - SCR活性、更强的水热稳定性和更好的抗硫能力方面比Cu - SAPO - 18和Cu - SAPO - 34更优异的原因。原位漫反射红外傅里叶变换光谱（DRIFTS）结果表明了反应中间体如 -NH₂、NH₃、NO₂、NO等的形成。Eley - Rideal（E - R）和Langmuir - Hinshelwood（L - H）反应机理都存在于铜基SAPO - 18和SAPO - 18/34共生沸石中，但L - H机理主导了NH - SCR反应，此外，Cu - SAPO - 34仅遵循“L - H”机理。
