Electrochemical generation of H2O2 in low ionic strength media on gas diffusion cathode fed with air

The electrogeneration of hydrogen peroxide in solution with low ionic strength using a gas diffusion cathode fed with air was investigated by linear sweep voltammetries and bulk electrolyses. The effect of applied current (15\u201345mAcm 122), solution pH (4\u201310), temperature (15\u201360 \u25e6C) and cell configuration (divided or undivided) on the H2O2 generation rate and current efficiency was evaluated. Experimental results showed that in Na2SO4 0.05MH2O2 can be produced with a satisfactory efficiency, i.e. 53%. Higher production rate was obtained in a two-compartment cell by increasing current density and pH and by decreasing solution temperature. A much lower efficiency (i.e. 30%) was obtained using the undivided cell, because, under these conditions, electrogenerated hydrogen peroxide was decomposed by anodic oxidation on Pt electrode