The influence of H 2 O or/and O 2 introduction during the low-temperature gas-phase sulfation of organic COS + CS 2 on the conversion and deposition of sulfur-containing species in the sulfated CeO 2 -OS catalyst for NH 3 -SCR

• Published in: Nanoscale Vol. 16; no. 3; pp. 1223 - 1237
• Main Authors: Xiong, Zhibo, Zhu, Yafei, Liu, Jiaxing, Du, Yanping, Zhou, Fei, Jin, Jing, Yang, Qiguo, Lu, Wei
• Format: Journal Article
• Language: English
• Published: England 18.01.2024
• ISSN: 2040-3364; 2040-3372
• DOI: 10.1039/D3NR04686A

Herein, the typical components of blast furnace gas, including H O and O , were introduced to improve the NH -SCR activity of the sulfated CeO -OS catalyst during the gas-phase sulfation of organic COS + CS at 50 °C. The characterization results demonstrate that the introduction of O or H O during gas-phase sulfation enhances the conversion of organic COS + CS on a cubic fluorite CeO surface and reduces the formation of sulfur and sulfates in the catalyst, but decreases the BET surface area and pore volume of the sulfated CeO -OS catalyst. However, the introduction of O or H O during the gas-phase sulfation increases the molar ratios of Ce /(Ce + Ce ) and O /(O + O + O ) on the sulfated CeO -OS catalyst surface, thus promoting the formation of surface oxygen vacancies and chemisorbed oxygen, and these properties of the catalyst are further enhanced by the co-existence of O and H O. Furthermore, the reduction of sulfates formed under the action of O or H O decreases the weak acid sites of the sulfated CeO -OS catalyst, but the few and highly dispersive sulfates present stronger reducibility, and the proportion of medium-strong acid sites of the catalyst increases. These factors help to improve the NH -SCR activity of the sulfated CeO -OS catalyst. Thus, there exists a synergistic effect of H O and O introduction during gas-phase sulfation on the physical-chemical properties and catalytic performance of the sulfated CeO -OS catalyst by organic COS + CS at 50 °C.