A Double Perovskite Oxide with A-Site Deficiency: A Facile Way to Yield a Boosted Propane Combustion Catalyst

Development of robust non-noble metal catalysts for combustive oxidation of volatile organic compounds (VOCs) at low temperatures is in high demand. A-site deficient perovskite catalysts synthesized by gel-combustion technique have been studied for the combustion of propane as a model for the abatement of hydrocarbon VOCs. Double perovskite oxides La2–xNiMnO6 with x = 0.0, 0.05, 0.1, and 0.15 have been prepared. As-prepared samples have been investigated within the temperature range of 200‒500°C and have shown an almost perfect selectivity to carbon dioxide. Certain levels of the A-site deficiency result in the development of more oxygen vacancies, improve oxygen mobility, and enhance the catalyst reducibility. However, an excessive A-site deficiency has been found to deteriorate the catalytic performance. The 72-h durability experiments on the most active sample, La2‒0.1NiMnO6 perovskite, demonstrate its good stability and H2O tolerance. Though the CO2 presence in a feed slightly altered the conversion of La2NiMnO6, and La2‒0.1NiMnO6 catalysts, a significant conversion change has been observed for the La2‒0.15NiMnO6 catalyst. Catalyst characterization techniques used in the study include XRD, BET, H2-TPR, O2-TPD, EPR, and ICP.