摘要
发展CeO_(2)基材料用于汽油车碳烟燃烧脱除可满足中国最新尾气排放法规的需要,也是实现中国轻稀土资源均衡利用的有效途径。结合该领域内他人研究成果和本团队进展,将吸附态富电子氧物种(O_(x)^(-))明确为汽油车颗粒物过滤器(GPF)气氛下CeO_(2)催化碳烟燃烧的主活性相。以此为基础建立的O_(x)^(-)“生成→溢流→湮灭/捕获→失活”模型可有效解释元素掺杂改性反而削弱CeO_(2)碳烟氧化能力这一“反常”现象。从该机理模型出发,归纳出“构建多级氧传递通道实现活性氧充分利用”和“设计催化剂(超)大孔结构匹配碳烟形貌”两种提高CeO_(2)基催化剂氧化碳烟能力的技术策略。依循这两种策略,充分优化CeO_(2)基催化剂的成分、结构与形貌,可实现模拟GPF工况下低温碳烟燃烧脱除,满足GPF被动再生的实用需求。
The development of CeO_(2)-based soot oxidation catalysts benefits not only the automobile emission control,but also the balance between the market demand and the natural abundance of the light rare-earth elements in China.In this perspective,based on the results from our group as well as others,the absorbed electron-rich O_(x)^(-) species were identified as the main active phases for soot catalytic combustion over CeO_(2) in simulated working conditions of gasoline particulate filters(GPFs).By focusing on the“generation→spillover→annihilation/trapping→deactivation”of these O_(x)^(-) species during reactions,a reaction model was put forward to rationalize the“abnormal”low soot oxidation activity of the(La-,Zr-)modified CeO_(2).According to this reaction model,“building up tandem oxygen delivery routes(e.g.MO_(x)→CeO_(2)→Ag)in catalysts”and“making the catalysts macro-porous fiber-like”should be two effective strategies to improve the catalysts’practicability for soot elimination in GPFs.
作者
刘爽
方子昂
吴晓东
Liu Shuang;Fang Ziang;Wu Xiaodong(School of Materials Science and Engineering,Ocean University of China,Qingdao 266100,China;School of Materials Science and Engineering,Tsinghua University,Beijing 100084,China)
出处
《中国稀土学报》
EI
CAS
CSCD
北大核心
2022年第3期351-365,共15页
Journal of the Chinese Society of Rare Earths
基金
国家重点研发计划项目(2017YFC0211102)
国家自然科学基金项目(22076176)
山东省高等学校青创科技支持计划项目(2019KJD001)
山东省自然科学基金项目(ZR2021YQ14)
中央高校基本科研业务费项目(202042002,202141008,202061047)资助。
关键词
CeO_(2)基催化剂
碳烟
汽油车颗粒物
反应机理
活性氧生成与利用
CeO_(2)-based catalyst
soot
gasoline particulate matter
reaction mechanism
formation and utilization of active oxygen
作者简介
刘爽(1988-),男,博士,副教授,研究方向:稀土催化材料,机动车尾气催化净化。E-mail:lius@ouc.edu.cn。
