抗水性天然气汽车尾气催化氧化催化剂研发  

DEVELOPMENT OF WATER-RESISTANT CATALYSTS FOR CATALYTIC OXIDATION OF NATURAL GAS VEHICLES EXHAUST

作　　者：刘世达 侯栓弟 Liu Shida;Hou Shuandi(SINOPEC(Dalian)Petrochemical Research Institute Co.,Ltd.,Dalian,Liaoning 116045)

机构地区：[1]中石化(大连)石油化工研究院有限公司,辽宁大连116045

出　　处：《石油炼制与化工》2023年第1期44-51,共8页Petroleum Processing and Petrochemicals

基　　金：中国石油化工股份有限公司合同项目(322068)。

摘　　要：制备了系列Pd/Al_(2)O_(3)基天然气汽车尾气净化催化剂并对其进行了改性处理,通过N_(2)吸附-脱附、X射线衍射、热稳定性测试、催化剂活性评价等手段考察了水热处理、焙烧、稀土金属改性等处理过程对催化剂活性和抗水性能的影响。结果表明:水热处理可以在催化剂表面产生大量羟基基团,进而在后续的焙烧过程中脱离形成大量氧缺陷位,促进金属活性中心的分散,增强活性中心与金属表面的相互作用;焙烧温度对水热处理后催化剂的活性有较大影响,随着焙烧温度的升高,经焙烧制得催化剂的比表面积和孔体积都明显增大;稀土金属助剂的引入不会明显改变催化剂的孔道结构,但是可以在一定程度上增强催化剂的水热稳定性;以丁醇为溶剂,经水热处理、650℃焙烧、质量分数2%镧改性制得了性能最优的1%Pd/HTT-2La-B-Al_(2)O_(3)催化剂,其在305℃下催化甲烷氧化反应的转化率达90%。A series of Pd/Al_(2)O_(3)-based catalysts for the purification of natural gas vehicle exhaust were developed and modified,and the effects of hydrothermal treatment,calcination temperature,and rare earth metal modification on the catalytic activity and water-resistant ability in methane oxidation were investigated by means of N_(2) adsorption-desorption,XRD,thermal stability test and catalyst activity evaluation.The results showed that hydrothermal treatment could generate a large number of hydroxyl groups on the surface of synthesized catalysts,which could then be separated from the catalyst to form a large number of oxygen defect sites during in the subsequent calcinations process,and promote the dispersion of metal active sites and strengthen the interaction between metal and supports.In addition,increasing calcination temperature could significantly affect the activity as well due to the enlarged pore volume and surface areas.The introduction of rare earth metal promoters did not change the pore structure of the catalyst obviously,but enhanced the hydrothermal stability of Pd/Al_(2)O_(3) catalysts to a certain extent.The 1%Pd/HTT-2La-B-Al_(2)O_(3) catalyst with the best performance was prepared by hydrothermal treatment,calcination under 650℃and modification with 2%of lanthanum using butanol as solvent.The conversion rate for methane oxidation on the catalyst was 90%at 305℃.

关 键 词：天然气汽车 尾气 甲烷催化氧化 水热处理 焙烧温度 助剂改性 

分 类 号：X734.2[环境科学与工程—环境工程] TQ426[化学工程]