Catalytic Performance of La<sub>0.6</sub>Ca<sub>0.4</sub>Fe<sub>1-x</sub>Ni<sub>x</sub>O<sub>3</sub>Perovskites in DME Oxidation

• 作者: Daniela Salinas Eduardo J. Delgado Gina Pecchi José Luis García Fierro Ruddy Morales
• 来源期刊: 催化剂现代研究(英文)
• 学科: 化学
• 关键词: DME Perovskites OXIDATION Iron NICKEL
• 年，卷（期）: 2015,（4）
• 页码范围: 97-106
• 页数: 10页
• 分类号: O6

摘要

Substituted La0.6Ca0.4Fe1-xNixO3 (0.0 ≤ x ≤ 1.0) perovskite-type oxides prepared by the amorphous citrate method have been investigated as catalysts in the dimethyl ether (DME) oxidation reaction. The samples with an x ≤ 0.3 composition show an orthorhombic structure, while the intermediate compositions with 0.5 ≤ x ≤ 0.9 show a less crystalline orthorhombic perovskite structure with segregated phases that increase upon increasing the Ni content. The progressive substitution of Fe3+ by Ni2+ in La0.6Ca0.4FeO3 entails the progressive formation of oxygen vacancies and Fe4+ species for Ni substitution degrees of x ≤ 0.5. For larger degrees of substitution with x > 0.7, segregated phases and a progressive loss of the perovskite structure are detected. The highest catalytic performance for the total combustion of DME is obtained from equimolar substitution in the B-site position (Fe0.5Ni0.5), in which a large extent of Fe4+ species and oxygen vacancies are present.