Electrolytes for Coal Electrolysis

Abstract

Electrolysis of coal in an aqueous solution to form carbon dioxide at the anode and hydrogen at the cathode has a thermodynamic cell potential of 0.21 volts. It is believed that a coal electrolysis cell can be developed which would lower the cost of hydrogen production over that of a water electrolysis cell. The coal electrolysis is believed to be dependent on the water activity, and thus, the electrolyte used may affect the overpotentials required to drive the reaction. In this study four electrolytes were investigated, 8.07 N H₂SO₄, 4.23 N HCl, 4.90 N NaOH, and 4.01 N NaCl. The half cell potential versus the current density profile was determined for each electrolyte with about five weight percent carbon black, and without carbon black. Carbon black was used to eliminate the varying amounts of impurities in coal samples.