Oxygen ion mobility

The zirconia sensor operates primarily on the principle of a concentration cell. It consists of a non-porous solid electrolyte layer fabricated from zirconia stabilized with yttria or calcia and exhibits high oxygen ion mobility. This layer is sandwiched between two porous and electrically conductive electrodes. 

This type of defect cluster increases the electronic conductivity in two ways (1) the oxygen ion mobility decreases because of the trapping of oxygen vacancies, and (2) the electronic conductivity increases since the carrier concentration, n = [Ce ce] increases due to the decrease in the reduction energy. 

Besides the aforementioned acidity and basicity, by which the performance of catalysts for the OCM reaction are significantly affected, also some secondary factors like oxygen ion mobility and trace-amount doping may play an important role. To evaluate such effects, which are still poorly understood, studies are required in which these factors are adjusted in a controllable way. Two investigations directed towards this goal are referred to in the following section. 

The use of ceria and ceria-based materials in catalytic science has been well established in recent decades. Several investigations have reported that different kinds of interaction between ceria and various metal oxides influence catalytic activity and facilitate an improvement in the dynamic performance in the removal of VOCs. Catalytic activity is a complex function of several factors, such as oxidation state, nature of the support, catalyst composition, preparation method, crystal structure, particle size and so on. Doping of ceria creates an additional structural defect that influences the oxygen storage/release properties. Further, oxygen ion mobility affects phase stability and the aging properties of CeOg, and increases catalytic activity. ... 

W. Araki, Y. Imai, T. Adachi, Mechanical stress effect on oxygen ion mobility in 8 mol % yttria-stabilized zirconia electrolyte. J. Eur. Ceram. Soc. 29, 2275-2279 (2009)... 

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