Wang Xiaobo, Guo Ning, Peng Jiaqi, Wang Yue, Li Haijie, Ren Dongdong, Gui Keting
School of Environmental Science, Nanjing Xiaozhuang University, Nanjing, 211171, Jiangsu, China.
College of Chemistry and Materials Science, The Key Laboratory of Electrochemical Clean Energy of Anhui Higher Education Institutes, Anhui Provincial Engineering Laboratory for New-Energy Vehicle Battery Energy-Storage Materials, Anhui Normal University, Wuhu, 241002, Anhui, China.
Environ Sci Pollut Res Int. 2023 Apr;30(17):50635-50648. doi: 10.1007/s11356-023-25912-x. Epub 2023 Feb 17.
Expecting to gain an excellent operating temperature window and superior catalytic activity of the catalyst in SCR reaction, the Fe-Ce bimetallic oxide catalyst was firstly prepared and sulfated with two different sulfation strategies by HSO. It is interestingly found that both the two sulfation strategies can significantly broaden the operating temperature window of the catalyst. In particular, the SFC and FCS both exhibit superior resistance to HO + SO, and the NO conversion of the SFC even displays no changes in the coexistence of HO and SO. The characterization results show that different sulfation strategies can generate amorphous sulfate species rather than bulk sulfate species. Furthermore, more surface-adsorbed oxygen as well as higher contents of Ce and Fe can be obtained on the sulfated catalysts, especially for the SFC catalyst. Meanwhile, different sulfation strategies will progressively enhance the redox ability and amounts of strong acid sites, which will contribute to broadening the operating temperature window for the NH-SCR reaction. Additionally, different sulfation methods do not change the reaction pathway of catalysts. However, the adsorption of ad-NH species and reactivity of ad-NO species are significantly changed. These lead to the reaction pathway shifts to E-R direct over the SFC and the promotion of E-R and L-H mechanisms over the FCS catalyst.
为了在选择性催化还原（SCR）反应中获得优异的操作温度窗口和催化剂的卓越催化活性，首先制备了铁铈双金属氧化物催化剂，并用硫酸氢根通过两种不同的硫酸化策略对其进行硫酸化处理。有趣的是，发现这两种硫酸化策略均能显著拓宽催化剂的操作温度窗口。特别是，顺序硫酸化法（SFC）和先铁后铈硫酸化法（FCS）均表现出对HO + SO的优异抗性，并且在HO和SO共存时，SFC的NO转化率甚至没有变化。表征结果表明，不同的硫酸化策略会生成无定形硫酸盐物种而非块状硫酸盐物种。此外，在硫酸化催化剂上可获得更多的表面吸附氧以及更高含量的铈和铁，尤其是对于SFC催化剂。同时，不同的硫酸化策略会逐步提高氧化还原能力和强酸位点的数量，这将有助于拓宽NH-SCR反应的操作温度窗口。此外，不同的硫酸化方法不会改变催化剂的反应途径。然而，吸附的NH物种的吸附和吸附的NO物种的反应性会发生显著变化。这些导致反应途径在SFC上转变为E-R直接反应，并在FCS催化剂上促进E-R和L-H机制。
