摘要
利用红薯淀粉生物模板耦合蔓延自燃烧法构筑了新型铈钨复合氧化物催化剂;研究了钨掺杂摩尔比、调平pH值和引燃温度等对其SCR脱硝的影响和晶相的演变规律。研究结果表明:红薯淀粉生物模板铈钨复合氧化物催化剂合适的钨掺杂摩尔比、淀粉离子比和离子浓度分别为4∶2、100 g/mol和1.0—2.0 mol/L。钨掺杂可抑制铈氧化物中CeO 2的结晶,细化其晶粒,提高了其脱硝性能;氨水调平提高了钨助剂对铈氧化物CeO 2晶体形成的抑制作用;当调平pH值增至7.0时其脱硝效率达到最高,进一步提高调平pH值其脱硝效率反而降低、甚至低于未调平催化剂。引燃温度由150增至500℃可抑制复合氧化物中铈、钨氧化物晶体的形成,其脱硝效率逐渐升高,但700℃引燃会增强CeO 2晶体的结晶度,降低其脱硝效率。
A novel cerium-tungsten mixed oxide catalyst was obtained via the sweet potato starch bio-template spread self-combustion method.The influence of tungsten doping,ammonia water titration and ignition temperature on its selective catalytic reduction of NO x with NH 3(NH 3-SCR)was investigated.The results indicate that the suitable molar ratio of tungsten doping,starch dosage and ion concentration are 4∶2,100 g/mol and 1.0-2.0 mol/L for the starch bio-template cerium-tungsten mixed oxide catalyst,respectively.The doping of tungsten inhibits the crystallization of CeO 2 in cerium oxide,and refines its grain size,thereby enhances its NH 3-SCR activity.The titration of ammonia water improves the depression of tungsten doping on the formation of CeO 2.When the pH value of mixed solution increases to 7.0,the NH 3-SCR activity of catalyst reaches the optimum,but the further enhancement of pH value instead decreases its catalytic performance,and is even lower than that of catalyst without titrating ammonia water.The enhancement of ignition temperature from 150 to 500℃inhibits the formation of cerium or/and tungsten oxide crystallite,and gradually increases its activity.Meanwhile,the ignition at 700℃enhances the crystallization of CeO 2 in catalyst,resulting in a rapid decrease of NH 3-SCR activity.
作者
李振壮
熊志波
何军飞
李承绪
屈小珂
宁星
吴水木
陆威
LI Zhen-zhuang;XIONG Zhi-bo;HE Jun-fei;LI Cheng-xu;QU Xiao-ke;NING Xing;WU Shui-mu;LU Wei(School of Energy and Power Engineering,University of Shanghai for Science&Technology,Shanghai 200093,China;SPIC Powder Plant Operation Technology(Beijing)Co.,Ltd.,Beijing 102209,China;Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering,Shanghai 200093,China)
出处
《化学工程》
CAS
CSCD
北大核心
2020年第5期16-20,74,共6页
Chemical Engineering(China)
基金
国家自然科学基金资助项目(51406118,51976129)
上海市青年东方学者岗位学者计划(QD2015017)。
关键词
SCR脱硝
铈钨复合氧化物
淀粉生物模板
蔓延自燃烧法
引燃
NH 3-SCR
cerium-tungsten mixed oxide
starch bio-template
spread self-combustion
ignition temperature
