Comparison of the catalysed decomposition of hydrogen peroxide over superconducting and insulating barium cuprates—kinetics of decomposition over Y 2 BaCuO 5

Catalytic activities of two non‐conducting cuprates (Ba 2 Cu 3 O 5 , Y 2 BaCuO 5 ) and a superconducting cuprate YBa 2 Cu 3 O 7–δ , prepared by two different methods, were compared using H 2 O 2 solution. The two non‐conducting barium cuprates were found to be about two orders of magnitude more active than the superconducting perovskite‐like YBa 2 Cu 3 O 7–δ . The near coincidence of the kinetic curves for the catalysed decomposition of H 2 O 2 over YBa 2 Cu 3 O 7–δ , prepared either from the perovskite‐like Ba 2 Cu 3 O 5 and Y 2 O 3 or from its components, proves that Ba 2 Cu 3 O 5 is essential in the formation of YBa 2 Cu 3 O 7–δ . First‐order kinetics were observed for the catalysed decomposition of H 2 O 2 solution over the non‐perovskite Y 2 BaCuO 5 at the initial stages of the reaction, similar to that of the superconducting perovskite catalyst. A tentative scheme of the possible catalytic reactions for the decomposition of H 2 O 2 solution over the insulator Y 2 BaCuO 5 is given.