In-situ synthesis of hydrogen peroxide using water electrolysis and Pd/MWCNTs catalyst

At room temperature and atmospheric pressure, water electrolysis and Pd/MWCNTs catalyst are used to investigate the feasibility of in-situ synthesizing hydrogen peroxide in a safe way. Meantime, the ordinary Ti/beta-PbO2 anode and graphite cathode are adopted to construct the water electrolysis system. During experiments, the features of Pd/MWCNTs catalyst are characterized by transmission electron microscope/energy dispersive spectrometer, X-ray diffraction and X-ray photoelectron spectroscopy. The effect of pH, current density, catalyst dosage, interelectrode distance, agitation speed and different cations on H2O2 concentration is studied. Energy consumption for different current density is analyzed, too. The results show that H2O2 concentration for the optimal conditions, namely current density of 20 mA/cm(2), pH of 3, catalyst dosage of 0.5 g, interelectrode distance of 20 mm and agitation speed of 460 rpm, can attain to about 28 mg/L in 90 min. Additionally, under the above conditions, H2O2 concentration for water including Mg2+ ion can rapidly get to about 36 mg/L in 30 min. E-m increases from 213.0 to 368.8 kWh/kg when current density varying from 10 to 25 mA/cm(2). However for the lowest current density of 5 mA/cm(2), its E-m is 288.5 kWh/kg and is very high, too. The used process is feasible for in-situ synthesis of hydrogen peroxide.