Synthesis and microstructure of La _{1− x} Ca _x CoO ₃ nanoparticles and their catalytic activity for CO oxidation

Abstract

Perovskite nanoparticles of La 1−x Ca x CoO 3 (x = 0, 0.2, 0.3, 0.5) were synthesized by the combustion method using polyvinyl alcohol (PVA) and corresponding metal nitrates. Microstructure of samples was characterized by high resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED) combined with x-ray diffraction (XRD). The nanoparticles were characterized by thermogravimetric and differential thermal analysis (TG-DTA) and BET (Brunauer-Emmet-Teller). A high surface area (15-21 m 2 g −1 ) at low temperature (600 °C) of samples was obtained. The optimal preparative conditions were PVA/metals 2:1 by mole, pH = 3 and 80 °C for gel formation. Perovskites exhibit a good catalytic activity in total oxidation of CO at the low temperature (<250 °C) of reaction.

Nanoscale Engineering of Structurally Stable Nd-Substituted LaCoO3 as An Electrode Material for Supercapacitors

“…The appearance of intensity peaks positioned at 2θ values of 23.26°, 33.13°, 40.88°, 47.56°, 53.60°, 59.19°, 69.55°, 74.45°, 79.23°, 83.94°, 88.61°was identified to emerge from (100), ( 110), ( 111), ( 200), ( 210), ( 211), ( 220), ( 330), ( 310), ( 311), (222) planes, respectively. The emerged intensity peaks matched well with the characteristic ICSD reference # 01-075-0279, 25 strongly exhibiting the pure phase existence of single-phase cubic perovskite structure of LaCoO 3 having Pm-3m space group as demonstrated in Fig. 2b.…”

Comparison of the nickel addition patterns on the catalytic performances of LaCoO3 for low-temperature CO oxidation

“…Several strategies have been reported to improve the catalytic performances or lower the 4 reaction temperature of perovskite oxides for CO oxidation, including the use of new synthesis method [14], the deposition on a high-surface-area support [8], and the doping of other transition metals on the surface or in the framework [15]. The principle of the former two is by altering the textural structure of catalyst, while that of the third is by changing the chemical compositions of catalyst, which seems more interesting as it has the potential to tune the natural properties (e.g., redox ability) of the catalyst, and has the possibility of inducing synergistic effect between the different metal oxides.…”