摘要
采用喷雾热分解法制备了一系列钙钛矿型催化剂La_(1-x)Al_xFeO_3(x=0、0.3、0.5、0.7),采用X射线衍射仪和扫描电子显微镜,表征了La_(1-x)Al_xFeO_3相组成和微观形貌,评价了催化剂表面化学形态和催化活性指标.在发动机试验台架上,对甲醇/柴油发动机尾气中的甲醛、甲醇、1,3-丁二烯和N_2O进行了催化降解试验.结果表明:在La_(1-x)Al_xFeO_3中掺杂适宜量的Al有助于提高催化剂活性,改善催化剂比表面积和孔容积.当Al掺杂量为0.5时,所制备的La_(0.5)Al_(0.5)Fe O_3催化剂对甲醇、甲醛、丁二烯和N_2O的起燃温度(T50)分别为192、172、180和212℃,完全转化温度(T90)分别为227、205、240和324℃,呈现了良好的低温催化活性.对甲醇、甲醛、1,3-丁二烯和N_2O最大比排放分别为5.2×10~3、0.6×10~3、0.02和11.23 mg·k W^(-1)·h^(-1).与原发动机比排放相比,转化率达到了92%以上.表明La0.5Al0.5Fe O_3为适宜用于甲醇/柴油发动机尾气中非常规排放物低温催化降解的催化剂.
Perovskite-type La（1-x）AlxFeO3（ x= 0,0.3,0.5,0.7） catalysts were prepared by spray pyrolysis method,and the catalysts were characterized by X-ray diffraction（ XRD）,scanning electron microscopy（ SEM） and X-ray photoelectron spectroscopy（ XPS）. The catalysts performances were optimized in a micro fixed-bed reactor through doping appropriate amount of Al into A sites of La（1-x）AlxFeO3. The catalytic degenerating tests,including methanol,formaldehyde,1,3-butadiene and nitrous oxide（ N2 O）,were carried out on emission test bench of methanol-diesel engine. The results showed that catalytic combustion activity of La（1-x）AlxFeO3 was improved through doping appropriate amount of Al,and the specific surface area and pore volume of catalysts increased accordingly. When doping amount of Al was 0. 5,the resultant La0.5 Al0.5 Fe O3 presented good low-temperature catalytic combustion activity for methanol,formaldehyde,1,3-butadiene and nitrous oxide（ N2 O）,their light-off temperature（ T50） of La（0.5）Al（0.5） Fe O3 were 192,172,180 and 212 ℃ respectively,their total conversion temperature（ T90） of La0.5 Al0.5 Fe O3 were 227,205,240 and 324 ℃ respectively,and their largest specific emissions were 5.2×10^3,0.6×10^3,0.02 and 11.23 mg·k W^-1·h^-1 respectively. In addition,their corresponding conversion rates were achieved over 92%. Therefore,it is verified that La0.5Al0.5 Fe O3 had the best low-temperature catalytic degenerating activity for irregular exhaust emissions of methanol-diesel engine.
作者
胡明江
吕春旺
杨师斌
王忠
HU Mingjiang 1 , LU Chunwang1, YANG Shibin1 , WANG Zhong2(1. School of Energy and Building Environmental Engineering, Henan University of Urban Construction, Pingdingshan 467036 2. School of Automobile and Traffic Engineering, Jiangsu University, Zhenjiang 21201)
出处
《环境科学学报》
CAS
CSCD
北大核心
2018年第4期1437-1445,共9页
Acta Scientiae Circumstantiae
基金
国家自然科学基金(No.51376083)
河南省高等学校重点科研项目(No.18A470002)~~
关键词
催化剂
喷雾热分解
柴油机
非常规排放
催化降解
甲醇/柴油二元燃料
catalysts
spray pyrolysis process
diesel engine
irregular emissions
catalytic degradation
methanol/diesel dual fuel
