Unraveling SO2-tolerant mechanism over Fe2(SO4)3/TiO2 catalysts for NOx reduction

• 作者: Chong Feng Lupeng Han Penglu Wang Xiangyu Liu Guangyuan Zhou Dengsong Zhang
• 来源期刊: 环境科学学报（英文版）
• 年，卷（期）: 2022,（1）
• 页码范围: 340-350
• 页数: 11页
• 语种: 英文

摘要

Developing low-temperature SO2-tolerant catalysts for the selective catalytic reduction of NOx is still a challenging task.The sulfation of active metal oxides and deposition of am-monium bisulfate deactivate catalysts,due to the difficult decomposition of the as-formed sulfate species at low temperatures (＜300 ℃).In recent years,metal sulfate catalysts have attracted increasing attention owing to their good catalytic activity and strong SO2 toler-ance at higher temperatures (＞300℃);however,the SO2-tolerant mechanism of metal sul-fate catalysts is still ambiguous.In this study,Fe2(SO4)3/TiO2 and Ce2(SO4)3//TIO2 catalysts were prepared using the corresponding metal sulfate salt as the precursor.These cata-lysts were tested for their low-temperature activity and SO2 tolerance activity.Compared to Ce2 (SO4)3/TiO2,Fe2 (SO4)3/TiO2 showed significantly better low-temperature activity and SO2 tolerance.It was demonstrated that less surface sulfate species formed on Fe2(SO4)3/TiO2 and Ce2(SO4)3/TiO2.However,the presence of NO and O2 could assist the decomposition of NH4HSO4 over Fe2(SO4)3/TiO2 at a lower temperature,endowing Fe2(SO4)3/TiO2 with better low-temperature SO2 tolerance than Ce2(SO4)3/TiO2.This study unraveled the SO2-tolerant mechanism of Fe2(SO4)3/Tio2 at lower temperatures (＜300 ℃),and a potential strategy is proposed for improving the low-temperature SO2-tolerance of catalysts with Fe2(SO4)3 as the main active component or functional promoter.