Insight into the promoting effect of support pretreatment with sulfate acid on selective catalytic reduction performance of CeO2/ZrO2 catalysts
Insight into the promoting effect of support pretreatment with sulfate acid on selective catalytic reduction performance of CeO2/ZrO2 catalysts
复制标题
探究硫酸载体预处理对CeO2/ZrO2催化剂选择性催化还原性能的促进作用
DOI：
10.1016/j.jcis.2021.10.191
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发表时间：
2022-02-15
影响因子：
9.9
通讯作者：
Pan, Xinxiang
中科院分区：
文献类型：
--
作者：
Han, Zhitao;Li, Xiaodi;Pan, Xinxiang
In this paper, sulfated ZrO2 were synthesized via precipitation and impregnation method, and the promoting effects of support sulfation on selective catalytic reduction (SCR) performance of CeO2/ZrO2 catalysts were investigated. The results revealed that sulfated ZrO2 could significantly enhance the SCR activity of CeO2/ZrO2 catalysts in a wide temperature range. Especially when S/Zr molar ratio was 0.1, CeO2/ZrO2-0.1S catalyst exhibited a large operating temperature window of 251 ti 500 degrees C and its N2 selectivity was 100 % in the temperature range of 150 ti 500 degrees C. Moreover, CeO2/ZrO2-0.1S catalyst possessed a superior low-temperature activity over 0.1S-CeO2/ZrO2 catalyst. After exposing to 100 ppm SO2 for 15 h, a high NO conversion efficiency of CeO2/ZrO2-0.1S catalyst (90.7 %) could still be reached. The characterization results indicated that ZrO2 treated with a proper dosage of sulfate acid was beneficial to enlarge the specific surface area greatly. Sulfated ZrO2 was also in favor of promoting the transformation of CeO2 from crystalline state to highly-dispersed amorphous state, and inhibiting the transformation of ZrO2 from tetragonal to monoclinic phase. It could also enhance the total surface acidity greatly with an increase in both Bronsted acid sites and Lewis acid sites, thus significantly improving NH3 adsorption on catalyst surface. Besides, the promoting effect of support sulfation on SCR performance of CeO2/ZrO2 catalysts was also related with the enhanced redox property, higher Ce3+/(Ce3++Ce4+) ratio and abundant surface chemisorbed labile oxygen. The in-situ DRIFTS results implied that nitrate species coordinated on the surface of CeO2/ZrO2-0.1S catalyst could participate in the Selective catalytic reduction with ammonia (NH3-SCR) reactions at either medium or high temperature, suggesting that both Eley-Rideal (E-R) and Langmuir-Hinshelwood (L-H) mechanisms might be followed in SCR reactions. (c) 2021 Elsevier Inc. All rights reserved.
