Complete oxidation of isopropanol over Cu4O3 (paramelaconite) coating deposited on fiberglass by CVD Original Research Article

Thin films of paramelaconite, tenorite and their mixtures were deposited on fiberglass substrate by chemical vapor deposition and catalytically evaluated by isopropanol oxidation at low temperatures between 150 and 275 °C. Copper oxides were deposited using bis(2,4-pentanedionato)copper(II) as a precursor and oxygen as carrier-reactant gas. Original crystalline phases deposited on fiberglass at different temperatures or formed subsequently were characterized by several analytical techniques. Films gave crystallite sizes from 6.5 to 8.4 nm and a thickness around 230 nm. The fiberglass with a paramelaconite film showed a relatively high catalytic activity, more than 40%, at 250 °C. Nevertheless, the fiberglass with a tenorite film exhibited a catalytic activity of only 10% at the same temperature. Above 250 °C the paramelaconite experienced a notable deactivation after which the catalytic activity decreased to 6.7% at 350 °C and after this, the catalyst could not be reused. This activity loss was probably due to changes in the chemical phases on fiberglass by effect of temperatures above 250 °C.