The promoting effect of S-doping on the NH3-SCR performance of MnOx/TiO2 catalyst
The promoting effect of S-doping on the NH3-SCR performance of MnOx/TiO2 catalyst
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S掺杂对MnOx/TiO2催化剂NH3-SCR性能的促进作用
DOI：
10.1016/j.apsusc.2019.144694
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发表时间：
2020-04-01
影响因子：
6.7
通讯作者：
Shen, Zhongyun
中科院分区：
文献类型：
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作者：
Liu, Xuesong;Yu, Qifan;Shen, Zhongyun
采用溶胶-凝胶法制备了一系列S掺杂的MnOx/TiO 2催化剂，以提高SCR性能。当S：Ti摩尔比为0.05：1时，催化剂的低温SCR性能最好，活性温度窗口最宽。根据各种分析结果，通过S4+取代Ti 4+，在TiO 2晶格中掺入适量的S，形成Ti-O-S键，随着表面积的增加，表面Mn 4+物种和活性氧物种（O-2（-））沿着增加。这些增强的性能改善了适当的S掺杂的MnOx/TiO 2催化剂的布朗斯台德酸中心和氧化还原性能。S掺杂的这些优点可以从根本上提高MnOx/TiO 2催化剂的dc-NOx能力。同时，原位DRIFT实验表明，适当的S掺杂后，吸附的NH 4+和气相NO2物种大大增加，沿着增加的是吸附的NH3和NOx物种的反应活性。在SCR反应中，S掺杂催化剂同时发生了E-R和L-H机理，而S掺杂的促进作用是通过促进L-H途径实现的。
A series of S-doped MnOx/TiO2 catalysts were prepared by sol-gel method for the purpose of enhancing SCR performance. The obtained catalyst with mole ratio of S:Ti = 0.05:1 exhibited the best low temperature SCR performance and the widest active temperature window. According to the results of various analyses, the proper S was doped into TiO2 lattice via the replacement of Ti4+ by S4+ to generate Ti-O-S bond, along with increasing surface area, more surface Mn4+ species and more active oxygen species (O-2(-)). These enhanced properties improved the Bronsted acid sites and redox property of the properly S-doped MnOx/TiO2 catalyst. These advantages of S doping can essentially benefit the dc-NOx ability of MnOx/TiO2 catalysts. Meanwhile, the in situ DRIFT experiments revealed that the adsorbed NH4+ and gas-phase NO2 species were greatly increased after proper S-doping, along with the enhanced reactivity of the adsorbed NH3 and NOx species. Both E-R and L-H mechanisms occurred on the S-doped catalysts, while the promoting effect of S-doping was performed by facilitating the L-H route during SCR reaction.