可还原性氧化物负载铜基催化剂CO-SCR性能研究  

Research on CO-SCR performance of reducible oxidesupported copper-based catalysts

作　　者：鲁冬 杜亚丽 刘江宁 武超辉 范昭阳 安霞[1] 吴旭[1] LU Dong;DU Yali;LIU Jiangning;WU Chaohui;FAN Zhaoyang;AN Xia;WU Xu(College of Chemistry,Taiyuan University of Technology,Taiyuan 030024,China;College of Chemistry and Chemical Engineering,Jinzhong University,Jinzhong 030619,China)

机构地区：[1]太原理工大学化学学院,太原030024 [2]晋中学院化学化工学院,山西晋中030619

出　　处：《功能材料》2022年第11期11007-11014,共8页Journal of Functional Materials

基　　金：国家自然科学基金资助项目(51978436);中国博士后科学基金资助项目(2020M670706);国家自然科学基金资助项目(52000092);山西省自然科学基金资助项目(201901D211445)。

摘　　要：环境友好型铜氧化物因适宜的氧化还原性被认为是极具潜力的CO-SCR脱硝催化剂,然而高温易烧结、分散性差成为限制其应用的关键。铜氧化物与适宜载体的协调复合通常可分散铜物种,克服其现有缺陷,同时提升催化活性。基于此,论文优选可还原性氧化物(CeO_(2)、γ-Fe_(2)O_(3))为载体,采用传统浸渍法制备了负载量为2.5%(质量分数)铜基催化剂(CuO_(x)/CeO_(2)和CuO_(x)/γ-Fe_(2)O_(3)),同时选用CuO作为参比催化剂,系统研究了可还原性载体对铜基催化剂理化性质、脱硝性能的影响规律。研究结果表明,载体的引入均不同程度的提升了铜氧化物的催化活性,其中以CeO_(2)为载体的铜基催化剂(CuO_(x)/CeO_(2))不仅展现了更优SCR催化活性、更高的N 2选择性,还具备更宽的活性温窗。借助XRD、H_(2)-TPR、NO-TPD、SEM+EDX-Mapping、XPS、In situ DRIFTs等表征分析发现,相比于γ-Fe_(2)O_(3)载体,CeO_(2)载体更有利于提升Cu物种的分散度、优化Cu物种的价态分布、增加表面活性位点。研究结论将为后期构筑高性能铜基SCR催化剂提供重要参考价值。Environmental friendly copper oxides were supposed as the potential CO-SCR denitrification catalysts due to the suitable redox capacity.Despite that,sintering at higher temperature and the poor dispersity and stability of CuO_(x) species remain the main factor to restrict their further application.Generally,the high dispersion of copper species could be achieved via the coordinated combination of copper oxides and appropriate supports,thus overcoming the present disadvantages of copper-based oxides and improving catalytic activity.Based on this,herein,the reducible oxides(CeO_(2),γ-Fe_(2)O_(3)) were selected as the support,where the CuO_(x)/CeO_(2) and CuO_(x)/γ-Fe_(2)O_(3) catalysts(loading capacity of CuO was 2.5wt%)were prepared by traditional impregnation method,and the pure CuO was selected as the reference catalyst.Meanwhile,the influence of reducible support on the physicochemical properties and denitrification performance of copper-based catalyst was systematically studied.The results displayed that the introduction of the support improved the catalytic activity of copper oxides to some extent,where the CuO_(x)/CeO_(2) catalyst with CeO_(2) as support not only showed better SCR catalytic activity,higher N_(2) selectivity,but also possessed the wider temperature window of activity.In addition,serious of characterizations(XRD,H_(2)-TPR,NO-TPD,SEM+EDX-Mapping,XPS,In situ DRIFTs and so on)analysis revealed that compared withγ-Fe_(2)O_(3),introducing CeO_(2) as the support was more conducive to improve the dispersion of CuO_(x) species,optimize the valence distribution of CuO_(x) species,as well as increase the surface active site.This work may serve as an important reference for fabricating Cu-based catalyst supported on reducible oxide with superior performance in potential applications for CO-SCR.

关 键 词：一氧化碳选择性催化还原 Cu基催化剂 可还原性载体 氮氧化物 低温 

分 类 号：N34[自然科学总论] O614[理学—无机化学] X51[理学—化学]