Generation of electricity using cleaner processes and more efficient use of energy are becoming increasingly important. Solid oxide fuel cells (SOFC), which can convert gas to electricity via an electrochemical reaction, are very attractive materials with regards to electricity production and energy utilisation due to the following:
- SOFC have an electrical efficiency of >50%, total efficiency >80% (vs Coal ~25%)
- SOFC emit 60% less CO2 than Coal, with no NOX or SOX emissions
- No combustion, no noise, European CE approved
- Operate on Natural Gas, LPG, Ethanol, Bio-diesel, Hydrogen

One of the main challenges faced in the development of SOFC technology is the production of the doped solid oxide used as an electrolyte in the fuel cell. Due to the conditions under which SOFC’s operate (600-1000 ◦C) the properties of the electrolyte (thermal stability, conductivity) are extremely important. The main challenge is to produce doped solid oxides with very consistent properties (i.e. doped solid oxides that are highly homogenous with very consistent chemical and physical characteristics). In this study we have investigated the chemistry involved in the formation of a commonly used SOFC electrolyte, yttria stabilised zirconia (YSZ). A number of aspects of the formation of YSZ at different pH were investigated including the structures of aqueous phase intermediates and the chemical and physical properties of intermediate precipitates. It was found that minor changes in solution pH have a significant effect on the chemistry of YSZ formation from an ammonium zirconium carbonate species.