College of Environmental Science and Engineering, Dalian Maritime University, Dalian 116026, China.
College of Environmental Science and Engineering, Dalian Maritime University, Dalian 116026, China.
J Colloid Interface Sci. 2022 Sep 15;622:1-10. doi: 10.1016/j.jcis.2022.04.110. Epub 2022 Apr 25.
Different Cu precursors were adopted to adjust the isolated Cu ions and CuO species in the Cu-SSZ-13 catalysts. The Cu ions were mainly located at eight-member rings in the catalysts with the Cu precursors of Cu(NO) (Fresh-I) and CuSO (Fresh-II), while that located at six-member rings in the catalysts with the Cu precursors of CuCl (Fresh-III) and Cu(CHCOO) (Fresh-IV). All catalysts showed>90% of NO conversion and 100% of N selectivity at 200-680 °C. Fresh-I and Fresh-II catalysts showed an unexpected increase of the high-temperature activity after hydrothermal treatment. The characterizations revealed that the hydrothermal treatment promoted the production of CuO species, which accelerated the adsorption of NO species to enhance the high-temperature SCR activity. Moreover, the SCR reaction pathway changed from Langmuir-Hinshelwood to Eley-Rideal mechanisms for the Fresh-II catalyst after the hydrothermal treatment, which was verified by in situ DRIFTS.
采用不同的 Cu 前驱体来调整 Cu-SSZ-13 催化剂中孤立的 Cu 离子和 CuO 物种。Cu 离子主要位于催化剂的八元环中，Cu(NO)（Fresh-I）和 CuSO（Fresh-II）为前驱体；而 CuCl（Fresh-III）和 Cu(CHCOO)（Fresh-IV）为前驱体时，Cu 离子位于六元环中。所有催化剂在 200-680°C 时均表现出>90%的 NO 转化率和 100%的 N 选择性。经水热处理后，Fresh-I 和 Fresh-II 催化剂的高温活性出人意料地增加。表征结果表明，水热处理促进了 CuO 物种的生成，从而加速了 NO 物种的吸附，提高了高温 SCR 活性。此外，水热处理后，Fresh-II 催化剂的 SCR 反应途径从 Langmuir-Hinshelwood 机制转变为 Eley-Rideal 机制，这通过原位 DRIFTS 得到了验证。
