硫酸浓度对Mn改性稀土尾矿催化剂NH_(3)-SCR脱硝性能的影响  

Influence of Sulfuric Acid Concentration on the NH_(3)-SCR Denitration Performance of Mn-Modified Rare Earth Tailings Catalysts

作　　者：侯丽敏 胡志斐 乔超越 武文斐[1,3] HOU Li-min;HU Zhi-fei;QIAO Chao-yue;WU Wen-fei(Key Laboratory of Efficient and Clean Combustion in Inner Mongolia Autonomous Region,School of Energy and Environment,Inner Mongolia University of Science&Technology,Baotou 014010,China;State Key Laboratory of Integrated Exploitation of Bayan Obo Multi-Metal Resources,Inner Mongolia University of Science&Technology,Baotou 014010,China;Province and Ministry Co-construction Collaborative Innovation Center of Integrated Exploitation of Bayan Obo Multi-Metal Resources,Inner Mongolia University of Science and Technology,Baotou 014010,China)

机构地区：[1]内蒙古科技大学能源与环境学院内蒙古自治区清洁燃烧重点实验室,内蒙古包头014010 [2]内蒙古科技大学白云鄂博矿多金属资源综合利用国家重点实验室,内蒙古包头014010 [3]内蒙古科技大学白云鄂博共伴生矿资源高效综合利用省部共建协同创新中心,内蒙古包头014010

出　　处：《稀有金属与硬质合金》2022年第6期46-51,共6页Rare Metals and Cemented Carbides

基　　金：国家自然科学基金项目(51866013);国家重点研发计划“973”项目(2020YFC1909102);内蒙古自然科学基金项目(2020BS05030,2019ZD13);内蒙古自治区直属高校基本科研业务经费项目;内蒙古自治区本级事业单位引进人才科研启动支持经费项目。

摘　　要：利用硫酸预处理白云鄂博稀土尾矿,随后采用浸渍法使其负载5%乙酸锰,经微波焙烧制成脱硝催化剂,考察了硫酸浓度(0、0.5、1、3 mol/L)对催化剂脱硝性能的影响。通过XRD、NH_(3)-TPD、H2-TPR和XPS对催化剂进行了表征。脱硝活性测试结果表明:催化剂在100~250℃的脱硝活性随着硫酸浓度的增加先提高后降低,当硫酸浓度为0.5 mol/L时达到最佳。较高浓度(3 mol/L)的硫酸大幅度降低了催化剂的低温活性。0.5 mol/L硫酸处理的催化剂具有较宽的温度窗口,在150~250℃范围内均有较好的活性,200℃时氮氧化物转化率达到92%。表征结果表明:负载的Mn元素以非晶态存在或高度分散在稀土尾矿表面;随着硫酸浓度的增加,催化剂表面Mn4+的浓度降低,其NH_(3)吸附能力和氧化还原能力均降低,从而脱硝性能降低。Bayan Obo rare earth tailings were pretreated with sulfuric acid and then loaded with 5%manganese acetate by impregnation and roasted by microwave to prepare denitration catalysts.And the effects of sulfuric acid concentration(0 mol/L,0.5 mol/L,1 mol/L,and 3 mol/L)on the denitration performance of the catalysts were investigated.The catalysts were characterized by XRD,NH_(3)-TPD,H2-TPR,and XPS.The results of denitration activity tests show that the denitration activity of the catalysts at 100~250℃increases at first and then decreases with the increase of sulfuric acid concentration,and reaches the best when the sulfuric acid concentration is 0.5 mol/L.The higher concentration(3 mol/L)of sulfuric acid deteriorates the originally good low-temperature activity of the catalyst.The catalyst treated with 0.5 mol/L sulfuric acid has a wide temperature window with good activity in the range of 150℃to 250℃and the conversion rate of nitrogen oxides reaches 92%at 200℃.The characterization results show that the loaded manganese exists in amorphous state or is highly dispersed on the surface of the rare earth tailings.The concentration of Mn4+on the catalyst surface decreases with the increase of sulfuric acid concentration,and both the ammonia adsorption capacity and redox capacity of the catalysts decrease,thereby reducing the denitration activity.

关 键 词：稀土尾矿 硫酸预处理 Mn改性 催化剂 NH_(3)-SCR 低温活性 

分 类 号：TQ426.6[化学工程]