Correlation of catalytic oxidation and ionic conductivity properties of nanostructured gadolinium-doped ceria

• Published in: Materials science & engineering. B, Solid-state materials for advanced technology Vol. 266; p. 115060
• Main Authors: Godinho, Mario, Rodrigues, Murillo H.M., F. Gonçalves, Rosana de, Roca, Román Alvarez, Longo, Elson, Mota, Fabiana Villela, Fajardo, Humberto V., Balzer, Rosana
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.04.2021; Elsevier BV
• Subjects: Catalytic activity; Catalytic oxidation; Cerium gadolinium oxides; Cerium oxides; Conductors; Coprecipitation; Gadolinium; Gadolinium-doped ceria; Hexanes; Ion currents; Ions; N-hexane; Oxidation; VOCs; Volatile organic compounds; Catalytic oxidation; Gadolinium-doped ceria; Coprecipitation; N-hexane
• ISSN: 0921-5107; 1873-4944
• DOI: 10.1016/j.mseb.2021.115060

[Display omitted] •The highest ionic conductivity and conversion at 400 °C were obtained for the Ce0.85Gd0.15O1.9−δ sample.•The Ce0.85Gd0.15O1.9−δ presented the best catalytic activity.•The increase in the superoxide formation and the oxygen mobility contribute to the catalytic activity performance. This paper reports the relationship between ionic conductivity and catalytic activity of ionic conductors based on gadolinium-doped ceria (GDC) at different temperatures. The samples have been characterized by transmission electron microscopy techniques, and the results indicated a highly homogeneous particle size, which confirmed their nanometric size. Afterward, the structure determined using X-ray diffraction analysis has been used to analyze the effect of dopant insertion. Lastly, ionic conductivity data were obtained using the impedance technique and were compared with the conversion rates of volatile organic compounds using GDC heterogeneous catalysts. The samples containing 15% gadolinium presented higher catalytic activity for the oxidation of n-hexane (82,5%) as well as higher ionic conductivity at 400 °C (3.09 × 10−4 S·cm−1). An attempt is made to correlate conductivity and catalytic oxidation in terms of oxygen mobility, vacancies, and superoxide formation.