Hydrogen production via solid electrolytic routes

Hydrogen is considered as a sustainable fuel, especially for transport applications, if it is generated using renewable energy sources. Currently, most of the hydrogen is generated from fossil fuels for use in ammonia and fertilizer production, and petrochemical and metallurgical industries with very little use as an energy carrier. In future, the use of hydrogen as a transport fuel in fuel cell or internal combustion engine vehicles is likely to increase stemming from concern over potential oil shortage and greenhouse gas and other pollutant emissions. Electrolysis of water is one of the key technologies to generate hydrogen both at small (distributed productions at end-use sites) and large scale. Solid electrolytic routes have been under consideration for many years with low-temperature systems mainly based around polymer electrolyte membranes now reaching commercialization status. High-temperature solid electrolyte systems can take advantage of utilizing the waste heat from nuclear or coal-fired power plants or other chemical processes to reduce the electrical energy required, thus boosting the overall system efficiency for steam electrolysis. An overview of various solid electrolytic routes for hydrogen production, materials used, performance, and technology status is given. (C) 2012 John Wiley & Sons, Ltd.