钨掺杂对MnCeTiO_(x)催化剂脱硝性能的影响及其机理  

Effects and Mechanism of W Doping on De-NO_(x) Performance of MnCeTiO_(x) Catalyst

作　　者：姜正雄 高宇[2] 吴玺田 韩志涛[2] JIANG Zheng-xiong;GAO Yu;WU Xi-tian;HAN Zhi-tao(Shanghai Electric Power Generation Environmental Protection Engineering Co.,Ltd.,Shanghai 201612,China;Marine Engineering College,Dalian Maritime University,Dalian 116026,China)

机构地区：[1]上海电气电站环保工程有限公司,上海201612 [2]大连海事大学轮机工程学院,大连116026

出　　处：《科学技术与工程》2022年第20期8972-8979,共8页Science Technology and Engineering

基　　金：国家自然科学基金(51779024);辽宁省自然科学基金(2020MS130)。

摘　　要：氮氧化物(NO_(x))排放会对生态环境和人类健康构成严重威胁。选择性催化还原技术(selective catalytic reduction,SCR)能够高效去除氮氧化物,已被广泛应用于固定源和移动源烟气脱硝领域。MnCeTiO_(x)催化剂是一种具有较好脱硝性能的SCR催化剂。采用共沉淀法制备了一系列W掺杂的MnCeTiO_(x)催化剂,考察了W掺杂对催化剂脱硝性能和抗硫中毒性能的影响。采用X射线衍射、X射线光电子能谱、原位漫反射傅里叶变换红外光谱等表征手段对MnCeTiO_(x)和W_(0.15) MnCeTiO_(x)催化剂的晶体结构、表面元素价态和表面反应活性物种进行了表征分析。探讨了W掺杂提高MnCeTiO_(x)催化剂脱硝性能和抗硫性能的反应机理。结果表明:W掺杂一方面有利于提高催化剂表面Ce^(3+)和Mn^(3+)物种的相对含量,另一方面使催化剂表面参与SCR反应的活性物种更加丰富,从而提高了催化剂脱硝性能和N_(2)选择性。W掺杂也有利于抑制NH_(4)HSO_(4)物种在催化剂表面的生成和沉积,从而提高了催化剂的抗硫中毒性能。The emission of nitrogen oxides(NO_(x))imposes a serious threat to ecological environment and human health.Selective catalytic reduction(SCR)technology is considered as an efficient method to remove NO_(x).It has been widely used to remove NO_(x) which emit from stationary source and mobile source.MnCeTiO_(x) catalyst is a kind of SCR catalyst with high de-NO_(x) performance.A series of W doped MnCeTiO_(x) catalysts were prepared by coprecipitation method.The effects of W doping on de-NO_(x) performance and sulfur resistance of catalysts were investigated.The crystal structure,chemical states of surface elements and surface active species of MnCeTiO_(x) and W_(0.15) MnCeTiO_(x) catalysts were characterized by X-ray diffraction,X-ray photoelectron spectroscopy and in-situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS)methods.The reaction mechanism of improving de-NO_(x) performance and sulfur resistance of MnCeTiO_(x) catalyst through W doping was discussed.The results show that W doping can increase the relative content of Ce^(3+) and Mn^(3+) species on catalyst surface,and enrich the active species which can participate in SCR reaction on catalyst surface,thus improve the de-NO_(x) performance and N_(2) selectivity of catalyst.W doping can also inhibit the formation and deposition of NH_(4)HSO_(4) species on catalyst surface,thus improve the sulfur resistance of catalyst.

关 键 词：钨掺杂 MnCeTiO_(x)催化剂 氮氧化物(NO_(x)) 选择性催化还原 

分 类 号：X511[环境科学与工程—环境工程]