以活性炭为模板制备钙钛矿型LaMnO_3催化剂

Preparation of Perovskite-Type LaMnO_3 Catalyst Using Active Carbon as Template

为提高钙钛矿型氧化物催化剂的比表面积,以活性炭为硬模板剂,采用浸渍法制备了一系列不同活性炭用量的LaMnO3催化剂,利用XRD,BET,SEM,TG,H2-TPR等手段对催化剂进行了表征,并考察了其催化甲苯燃烧的活性。实验结果表明,适当用量的活性炭模板剂能明显提高LaMnO3催化剂的比表面积和结晶度,改善催化剂的氧化还原性,从而提高其催化甲苯燃烧的活性;当活性炭用量为0.5 g(以理论上制备5.0 g催化剂为基准)时,制得的LaMnO3催化剂的比表面积最大(可达28.6 m2/g),且活性最高,在进料混合气中甲苯的含量为0.88%(φ)、气态空速为20 L/(g.h)的反应条件下,甲苯的完全转化温度约为260℃。

In order to increase the specific surface areas of pervoskite-type oxide catalysts,a series of LaMnO3 catalysts were prepared by impregnation using active carbon as hard template,and were characterized by means of XRD,BET,SEM,TG and H2-TPR.Their catalytic combustion activities were tested using toluene combustion as probe reaction.The results indicated that the addition of active carbon with appropriate dosage could increase the specific surface area and crystallinity of the LaMnO3 catalysts,and could improve their redox properties,so the catalytic activities of the LaMnO3catalysts were improved.When the dosage of active carbon was 0.5 g（based on 5.0 g catalyst in theory）,the specific surface area of the LaMnO3catalysts could reach the largest,about 28.6 m2/g,and the highest catalytic activity was obtained also.Under the reaction conditions of φ（toluene） 0.88%（mixed gas of air and toluene） and GHSV 20 L/（g.h）,the temperature for the complete conversion of toluene over the catalyst was 260 ℃.