摘要
首先,采用沉积-沉淀法制备了与镁铝尖晶石(Mg Al2O4,简称MA)载体复合的镧锶锰钙钛矿(La_(0.8)Sr_(0.2)MnO_3,简称LSM)催化剂LSMn,考察了MA与LSM的物质的量比(n)、前驱体老化和焙烧温度系列制备条件的影响,在程序升温微反应器中测试了LSMn粉体对低浓度甲烷催化燃烧反应的活性,并用FTIR、H2-TPR、BET、XRD和SEM手段对催化剂进行表征。结果表明:在10℃老化和800℃下焙烧的LSM4性能最佳,T50为489.4℃,活化能Ea=112.5 kJ/mol,BET比表面积仍有81.6 m2/g,表现出较好的抗烧结性能。然后,用浆料涂覆法依次将第二载体(MA)和LSM4粉体涂覆在Fe-Cr-Al合金丝网上制得了丝网蜂窝催化剂。考察了第二载体及LSM/4MA粉体涂覆量的影响,在空速40000 h–1条件下测试了蜂窝催化剂的活性,结果表明,MA的最佳涂覆厚度约20mm,LSM/4MA的最佳涂覆量约为2.65 mg/cm2,甲烷转化率30%以上。
The composite powders of La0.8Sr0.2MnO3(LSM) perovskite and MgAl2O4(MA) spinel, named as LSMn were prepared by deposition-precipitation method. The factors affecting preparation conditions, such as molar ratio of MA to LSM(n), aging temperature and calcination temperature of precursors were investigated. The activity of LSMn samples for the catalytic combustion of air diluted methane was evaluated in a temperature-programmed micro reactor. The properties of catalysts were characterized by FTIR, H2-TPR, BET, XRD and SEM. The results showed that when precursor was aged at 10 ℃ and calcined at 800 ℃, the resulting LSM4 sample demonstrated the best activity(T50=489.4 ℃;Ea=112.5 kJ/mol) and exhibited excellent sintering resistance with a specific surface area of 81.6 m^2/g. The second carrier MA and LSM4 powders were then coated on Fe-Cr-Al wire mesh by dip-coating method to prepare wire mesh honeycomb catalysts. The effects of MA loading and LSM4 coating on the catalytic combustion of 0.5% methane were investigated at GHSV of 40000 h^–1, respectively. The results revealed that the proper coating thickness of MA was around 20 mm, and the best loading of LSM4 was about 2.65 mg/cm^2. The methane conversion over this wire mesh honeycomb catalyst was above 30%.
作者
王忍青
段伟杰
黄波
江志东
WANG Ren-qing;Duan Wei-jie;HUANG Bo;JIANG Zhi-dong(School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China;ShanghaiKey Lab of Electric Insulation and Thermal Aging, Shanghai 200240, China)
出处
《精细化工》
EI
CAS
CSCD
北大核心
2019年第2期250-256,共7页
Fine Chemicals
