一氧化碳在高温超导体型的Ba2-xSrxYCu3O7-a上的催化氧化

用粉末XRD法、EXAFS法,激光喇曼散射法、热重法和高真空质谱TPD法研究了超导体型氧化还原催化剂Ba_(2-x)Sr_xYCu_3O_(7-α)(x=0,0.25, 0.50, 0.75, 1.00)的物理化学性质, 并用常压连续流动法测定了它们的CO催化氧化活性, 得到了催化剂氧化反应活性大小与催化剂的可失氧量(即晶胞中O_I 位置上的氧量)之间存在着线性关系的结论.

The Catalytic Oxidation of Co Over Ba2-xSrxYCu3O7-a

High temperature oxide superconducters Ba_(2-x)Sr_xYCu_3O_(7-a) (x=0, 0.25, 0.50, 0.75, 1.0, 1.25) was prepared using high purity BaCO_3, SrCO_3, Y_2O_2, CuO. The super-conducting transition temperature (T_c) of the samples was measured by the four-probe technique for resistivity and alternative current method for magnetic suscepti-bility. The properties of the superconductots were examined by using powder XRD method, EXAFS, laser Raman spectroscopy, TG and high vacuum mass spectroscopy TPD. The amount of substitution x is larger, the T_c is lower, the lattice parameters a, b, c and V are smaller and the occupation of oxygen is lower. The catalytic activity of these oxides for CO oxidation was also detected by continuous flow system at 1 atm. The easier released oxygen of these oxides O_I, the most active oxygen in the lattice, is the active center in catalytic oxidation by CO. The reaction mechnism is the same as that of Ba_2YCu_3O_(7-δ). Furthermore, there is a linear relationship between the catalytic activity and the amount of O_I.