Abstract
High-temperature electrochemical cells based on solid electrolytes have been considered for synthesis and production of hydrogen and a variety of other fuels and chemicals. Solid oxide electrolysis cells (SOECs) for example, are being developed for hydrogen production (from water), syngas production (from mixtures of water and carbon dioxide) and oxygen recovery (from water or carbon dioxide for space applications). The main attractive features of the SOEC are its simple chemistry, environmental compatibility and high electrical-to-hydrogen efficiency. Solid oxide fuel cell (SOFC type cells have been investigated for production of chemicals and cogeneration of electricity and chemicals (in this case, the cell is referred to as CSOFC); examples include production of C2 hydrocarbons and syngas from methane. The key features of the CSOFC include its high selectivity and the possibility to produce valuable chemicals such as hydrocarbons using methane-rich gases from non-fossil origins. Current state-of-the-art SOECs and CSOFCs, both fundamentally derived from the more advanced conventional SOFC technology are still in their feasibility/development stage. This paper discusses certain aspects in selected materials, performance and operation of the SOEC for hydrogen production from water and the CSOFC for production of C2 hydrocarbons from methane.