Chai Yanxiao, Zhang Guizhen, He Hong, Sun Shaorui
Beijing Key Laboratory for Green Catalysis and Separation, College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124, China.
ACS Omega. 2020 Oct 12;5(42):26978-26985. doi: 10.1021/acsomega.0c00018. eCollection 2020 Oct 27.
In this paper, density functional theory has been applied to study the mechanism of anti-SO poisoning and selective catalytic reduction (SCR) reaction on a MoO/VO surface. According to the calculation results, the SO molecule can be converted into SO on VO(010) and further transformed into NHHSO, which poisons VO. If VO and MoO are combined with each other, charge separation of VO and MoO, which are negatively and positively charged, respectively, occurs at the interface. In ammonium bisulfate liquid droplets on the MoO/VO surface, NH tends to adhere to the VO(010) surface and can be removed through the SCR reaction and HSO tends to adhere to the MoO(100) surface and can be resolved into SO and HO, which can be released into the gas phase. Thus, MoO/VO materials are resistant to SO poisoning. In the MoO/VO material, Brønsted acid sites are easily formed on the negatively charged VO(010) surface; this reduces the energy barrier of the NH dissociation step in the NH-SCR process and further improves the catalytic activity.
本文运用密度泛函理论研究了MoO/VO表面上抗SO中毒及选择性催化还原（SCR）反应的机理。根据计算结果，SO分子在VO(010)上可转化为SO，并进一步转化为NHHSO，从而使VO中毒。若VO与MoO相互结合，在界面处会分别发生带负电的VO和带正电的MoO的电荷分离。在MoO/VO表面的硫酸氢铵液滴中，NH倾向于附着在VO(010)表面，并可通过SCR反应去除，而HSO倾向于附着在MoO(100)表面，并可分解为SO和HO，进而释放到气相中。因此，MoO/VO材料具有抗SO中毒性能。在MoO/VO材料中，带负电的VO(010)表面易于形成布朗斯特酸位点；这降低了NH-SCR过程中NH解离步骤的能垒，并进一步提高了催化活性。
