Clean hydrogen generation through the electrocatalytic oxidation of ethanol in a Proton Exchange Membrane Electrolysis Cell (PEMEC): Effect of the nature and structure of the catalytic anode
Résumé
The electrocatalytic oxidation of ethanol was investigated in a Proton Exchange Membrane Electrolysis Cell (PEMEC) working at low temperature (20 degrees C) on several Pt-based catalysts (Pt/C, PtSn/C, PtSnRu/C) in order to produce very clean hydrogen by electrolysis of a biomass compound. The electrocatalytic activity was determined by cyclic voltammetry and the rate of hydrogen evolution was measured for each catalyst at different current densities. The cell voltages U-EtOH were recorded as a function of time for each current density. At 100 mA cm(-2), i.e. 0.5 A with the 5 cm(2) surface area PEMEC used, the cell voltage did not exceed 0.9 V for an evolution rate of about 220 cm(3) of hydrogen per hour and the electrical energy consumed was less than 2.3 kWh (Nm(3))(-1), i.e. less than one half of the energy needed for water electrolysis (4.7 kWh (Nm(3))(-1) at U-H2O = 2 V). This result is valid for the decomposition of any organic compound, particularly those originated from biomass resource, provided that their electro-oxidation rate is sufficient (>100 mA cm(-2)) at a relatively low cell voltage (U-cell < 1 V) which necessitates the development of efficient electrocatalysts for the electrochemical decomposition of this compound