Reduction of oxygen at a NaX-Ag composite electrode and its application to the determination of oxygen in aqueous media

A composite mixture Ag-NaX zeolite (silver concentration 16.7% w/w) is synthesized usingim-pregnation and thermal decomposition. For silver impregnation, a solution of an Ag acetylacetonate complex in acetone was used. Despite the quantity of silver applied was substantially less than it would be necessary to fill the inner pore space in the zeolite completely, some part of silver formed nanocrystallites and nanoparticles giving rise to a novel composite material. The composite powder was uniformed with soot (10% w/w) and applied onto a mirror-smooth graphite surface used as an electrode matrix. The reduction of oxygen on such a surface proceeded with activity comparable to that observed on the most active planes of the silver single crystal, Ag(100).