The catalytic activity of the ceramic superconductor YBa 2 Cu 3 O 7 − δ

The superconductivity of the ceramic solid YBa 2 Cu 3 O 7 − δ , prepared by heating Y 2 O 3 , BaCO 3 and CuO at 920°C for 22 h, was checked by the Meissner effect. Chemical analysis established the formula of the compound prepared. A thermostated aqueous suspension of the superconductor, treated with a solution of H 2 O 2 , produced oxygen, whose volume was measured at intervals in a gas burette. From the initial rates of the first‐order reaction at different temperatures, the activation enthalpy and entropy were 16 kJ mol −1 and −210 J K −1 mol −1 respectively. The rates of gas evolution were similar to those obtained when a MnO 2 sample was used as a catalyst. Neither the superconductor nor its semiconductor phase photocatalysed the decomposition of KMnO 4 solution. Evidence of the catalysed decomposition of N 2 H + 5 by the superconductor is presented.