Development of a Pt-Ir Bimetallic Nanoparticulated Electrocatalyst Deposited on MWCNT for an Electro-Fenton Process

Synthesis of a novel cathode of bimetallic Pt-Ir nanoparticles deposited on multiwall carbon nanotubes (MWCNT) by a microemulsion method is reported in this paper; the composite material was dispersed with Nafion to deposit a film onto Reticulated Vitreous Carbon (RVC), the modified electrode was used as catalyst in an electrochemical reactor for H2O2 generation. The bimetallic catalyst showed higher activity toward O2 reduction compared to Ir/MWCNT, Pt/MWCNT and MWCNT. The O2 reduction pathway was determined. Only the bimetallic catalyst was found to lead to the reduction of O2 to produce H2O2. A high H2O2 rate was produced with the bimetallic catalyst. This approach was employed to carry out the Fenton process. Experimental evidence for the generation of hydroxyl radicals (*OH) was provided by using coumarin and the fluorescence detection of its hydroxylated product (7-hydroxycoumarin). The Pt-Ir/MWCNT cathode showed very stable behavior and could be reused without decrease of the catalytic activity. This suggests its potential use in wastewater treatment application.