甲烷氧化偶联Ti-La-Li系混合氧化物催化剂

研究了Ti-La-Li三元氧化物的组成、结构及其对甲烷氧化偶联反应的催化性能；用XRD、IR、XPS和SEM等方法对催化剂进行表征，结果表明：在LiTi_xLa_(1-x)O_2系列催化剂中，随x值的不同，可生成LaTi_(1－y)Li_yO_(3-λ)、Li_2TiO_3、La_(0.66)TiO_(2.993)、La_2O_3和Li_(1.33)Ti_(1.66)O_4几种物相，其中，钙钛矿到三元复合氧化物LaTi_(1-y)Li_yO_(3-λ)是甲烷氧化偶联反应的主要活性相，活性位Li~＋-O~－-Ti~(3＋)的形成是活性提高的主要原因．Li_2TiO_3和La_(0.66)TiO_(2.993)是深度氧化活性相，而Li_(1.33)Ti_(1.66)O_4既无偶联活性，也无深度氧化活性．

Study of Methane Oxidative Coupling over Ti-La-Li Mixed Oxides

The composition and structures of Li-Ti-La minxed oxides as well as their catalytic activity for methane oxidative coupling have been studied by means of XRD 、XPS、IR、SEM、 and so on. The results indicate that by changing x value in Li La_(1-x)Ti_xO_2 oxides phases of La_2O_3、 La-Ti_(1-y)Li_yO_(3-λ)、 Li_2TiO_3 and La_(0.66)TiO_(2.993) are formd. Among them the complex oalde LaTi1-y LiyO3-λ is the active phase for methane oxidative coupling due to the formation of active site Li~+-O~--Ti~(3+), while Li_(1.33)Ti_(1.66)O_4 is not active for both methane oxidative coupling and deep oxidation.