Preparation of LaNiO 3 perovskite by oxalate and carbonate precursor method for utilization as catalyst for high-temperature decomposition of N 2 O

The mixed oxide LaNiO 3 with perovskite structure was prepared by two relatively new and unconventional methods including preparation and thermal decomposition of mixed metal oxalate or carbonate precursors. The intermediates were prepared by reaction in a highly concentrated suspension (paste). The thermal decomposition conditions of these intermediates were described, and the final calcination temperatures were determined, which were done using thermal analysis methods and X-ray diffraction. During the decomposition of mixed carbonates, one-phase LaNiO 3 is produced directly, and in case of decomposition of oxalates, a mixture of LaNiO 3 and La 2 O 3 is produced due to the formation of La 2 O 2 CO 3 during the heating. Catalytic decomposition of nitrous oxide at high temperature (650–930 °C) and high loading (GHSV = 350,000 h −1 ) has shown high LaNiO 3 activity, even at lower temperatures. The results were compared with the same compound obtained by co-precipitation and by solid-state reaction. Methods of preparation based on decomposition of oxalate and carbonate intermediates lead to the preparation of materials with appropriate composition, morphology, specific surface and high catalytic activity.