Preparation and catalase activity of gold-ceria composites

Gold-ceria composites (СеО₂)Au and (Au)CeO₂ which exhibited catalase activity towards H₂O₂ decomposition in an aqueous medium depending on their preparation conditions were formed in two stages in situ. In the presence of hydrazine dihydrochloride both the probability of the ceria formation and the catalase activity of (СеО₂)Au were found to decrease. The catalase activity was at a maximum for (СеО₂)Au when the gold nanoparticles were formed in the 1.0 mM HAuCl₄ medium and for (Au)CeO₂ when they were synthesized in 0.5–0.75 mM HAuCl₄ and 1.0 mM Na₃C₆H₅O₇. Boiling (СеО₂)Au and (Au)CeO₂ composites at ~80 kPa reduced their capacity to decompose H₂O₂.