Prospects for hydrogen production by water electrolysis to be competitive with conventional methods

The cost of electrolytic hydrogen is about 2-3 times the cost of hydrogen produced from natural gas or naphta because of high electricity costs. With the increasing cost of coal and the impeding unavailability of oil and natural gas in a few years, the only alternative method for hydrogen production on a large scale can be by water electrolysis using electricity derived from nuclear or solar energy. Attention is directed to current status of advanced water electrolysis cells, effects of temperature on electrode kinetic parameters, electrocatalysis of hydrogen and oxygen evolution reactions, and use of mixed oxides as oxygen electrodes. Other subjects discussed include selection and evaluation of separator materials for water electrolysis cells, hydroxyl ion transporting solid polymer electrolyte, and photoelectrochemical effects.