Design and optimization of electrochemical cell potential for hydrogen gas production

This study deals with the optimization of best working conditions in molten melt for the production of hydrogen (H-2) gas. Limited research has been carried out on how electrochemical process occurs through steam splitting via molten hydroxide. 54 combinations of cathode, anode, temperature and voltage have been investigated for the optimization of best working conditions with molten hydroxide for hydrogen gas production. All these electrochemical investigations were carried out at 225 to 300 degrees C temperature and 1.5 to 2.5 V applied voltage values. The current efficiency of 90.5, 80.0 and 68.6% has been achieved using stainless steel anodic cell with nickel, stainless steel and platinum working cathode respectively. For nickel cathode, an increase in the current directly affected the hydrogen gas flow rate at cathode. It can be hypothesized from the noted results that increase in current is directly proportional to operating temperature and applied voltage. Higher values were noted when the applied voltages increased from 1.5 to 2.5 V at 300 degrees C, the flow rate of hydrogen gas increased from 1.5 to 11.3 cm(3) min (-1), 1.0 to 13 cm(3) min (-1) in case of electrolysis @ stainless steel and @ graphite anode respectively. It is observed that the current efficiency of stainless steel anodic cell was higher than the graphite anodic cell. Therefore, steam splitting with the help of molten salts has shown an encouraging alternate to current methodology for H-2 fuel production. (c) 2020 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.