Oxide Substrate Effect Toward Electrocatalytic Enhancement of Platinum and Ruthenium-Selenium Catalysts

Titanium dioxide (anatase) and carbon composites were produced. The oxide was synthesized via the sol-gel technique in a carbon matrix. A chemical interaction was revealed by thermal differential analysis since the carbon decomposition temperature shifts in the presence of the oxide. Oxide-carbon composites were used as support for nanodivided platinum and ruthenium-selenide catalyst. The nanoparticles were selectively deposited onto the oxide by means of electron-hole pairs generated on the oxide sites under UV irradiation. A systematic study for Pt was performed as a function of the loading using the oxide-carbon composite substrate and carbon toward the oxygen reduction reaction. A specific activity (mA/cm(Pt)(2)) enhancement of 30% to 40%, at 0.9 V per reversible hydrogen electrode, with respect to carbon-supported samples, was obtained. This effect was also observed on the Ru-Se system and can be attributed to a catalyst-substrate effect.