钙钛矿SrFe_(1-x)Mn_xO_3催化剂:共沉淀法制备及催化甲烷燃烧的性能(英文)

Perovskite-Type SrFe_(1-x)Mn_xO_3 Catalysts: Preparation by Co-precipitation Method and Catalytic Performance for Methane Combustion

通过共沉淀法制备了SrFe1-xMnxO3钙钛矿催化剂。用XRD、TPR和TG-DSC技术对催化剂进行了物理性能表征,以甲烷催化燃烧为目标反应表征其催化性能,通过BET模型计算了其比表面积,通过阿伦尼乌斯方程计算了反应的表观活化能。结果表明用共沉淀法制备钙钛矿催化剂经700℃焙烧4 h后可以形成完整的钙钛矿晶型,样品都具有高的催化性能,但随着锰离子的掺杂,催化剂活性明显提高,其中SrMnO3催化剂具有较高甲烷催化燃烧活性,起燃温度T10%为435℃,至457℃甲烷完全转化。

Manganese substituted ferric perovskite-type catalysts were prepared by co-precipitation method. The title catalysts were calcined at 700 ℃ and characterized by XRD, TPR and TG-DSC techniques. The catalytic activity was evaluated using methane combustion as a model reaction. The specific surface area was calculated by BET model. The values of the apparent activation energy were estimated from the Arrhenius plots based on a CH4 first-order rate equation. The samples exhibit significant catalytic activity for methane combustion at 700 ℃. With increasing the substitution of Mn2＋, the activities of the catalysts are improved. Upon calcination at 700 ℃ the catalyst SrMnO3 shows an excellent activity for methane combustion （the conversion of 10% and 90% are obtained at 435℃ and 457 %, respectively）.