Study of the reactivity of Double-perovskite type oxide La1−xMxNiO4 (M = Ca or Sr) for chemical looping hydrogen production

Autor: Gustavo Torres Moure, Juan A. C. Ruiz, Marcus Antônio de Freitas Melo, Dulce Maria de Araújo Melo, Heloísa P. Macedo, V. R. M. Melo, RA Medeiros, Renata Martins Braga
Rok vydání: 2018
Předmět:
Zdroj: International Journal of Hydrogen Energy. 43:1406-1414
ISSN: 0360-3199
Popis: La2-xMxNiO4 perovskite oxygen carriers (OC) doped with Ca and Sr (x = 0.05 and 0.20) in the site La were prepared by microwave assisted combustion method and calcined at 800 °C for 2 h. A reactivity study was carried out applying pulses of H2, O2 and CH4. The reactions involved in each step, as well as H2 production, were studied to evaluate the redox properties of each OC. The crystalline structure, morphology, reduction and oxidation profiles were determined by XRD, SEM and TPR/TPO cycles, respectively. The results indicate that the dopant (Ca or Sr) strongly affect the structure and reactivity of the OC. The increase in dopant concentration increased the degree of crystallinity and the amount of the A2BO4 phase formed. The increase in dopant concentration decreased the reducibility of the perovskite. OCs doped with Ca showed higher conversion percentages, and also higher H2 production. In carriers doped with Sr no coke formation was observed.
Databáze: OpenAIRE