采用共沉淀法制备Ge改性TiO₂载体,考察了V-Mo-O/xGe-TiO₂催化剂低温氨选择性催化还原(NH₃-SCR)活性和抗硫稳定性。与传统V-Mo-O/TiO₂催化剂相比,Ge的加入可以显著提高催化剂在低温窗口下的脱硝活性,同时使催化剂具有较高的N₂选择性以及稳定的抗硫性。当Ge/Ti原子摩尔比为0.004时,催化剂在180℃时脱硝活性可达92%。N₂吸附-脱附、XRD分析结果表明,Ge的加入增加了催化剂的比表面积和介孔孔容,并稳定了TiO₂的锐钛矿晶型。NH₃-TPD、H₂-TPR以及XPS分析结果表明,Ge改性促进了V、Mo之间的相互作用,增加了V⁴⁺的含量,同时催化剂表面的Brønsted酸含量进一步增加,并产生额外的Lewis酸,增强表面对氨的吸附活化作用,从而使催化剂表现出低温高活性和高稳定性。

Ge modified TiO₂ support is prepared via coprecipitation method.The activity and sulfur resistance stability of V-Mo-O/xGe-TiO₂ catalyst are investigated in low temperature ammonia selective catalytic reduction (NH₃-SCR).Compared with traditional V-Mo-O/TiO₂ catalyst,the addition of Ge can significantly improve the denitration activity of the catalyst at the low temperature window,and make the catalyst have high N₂ selectivity and stable sulfur resistance.The denitration activity of the catalyst reaches 92% at 180℃ when the molar ratio of Ge/Ti atom is 0.004.It is indicated by N₂ adsorption desorption and XRD analysis that the addition of Ge increases the specific surface area and mesoporous volume of the catalyst,and stabilizes the anatase crystal form of TiO₂.The results from NH₃-TPD,H₂-TPR and XPS analysis show that Ge modification promotes the interaction between V and Mo,increases the content of V⁴⁺,further increases the content of Brønsted acid on the catalyst surface,and generates additional Lewis acid to enhance the adsorption and activation of ammonia on the surface,so that the catalyst shows high activity at low temperature and high stability.

李泽清(1996-),男,硕士研究生,研究方向为环保催化剂的研究,1715731484@qq.com。