A modified glycine–nitrate combustion method for one-step synthesis of LaFeO3

• Solid glycine-based precursor with NH4OH was prepared for combustion process.
• LaFeO3 was synthesized using VCS and SHS combustion modes.
• The SHS mode allows a preparation of high-purity LaFeO3 without calcinations step.
• Well-crystallized LaFeO3 shows a higher catalytic activity for soot oxidation.

A complex glycine–nitrate precursor of LaFeO3 has been synthesized with the addition of ammonia. Fixation of ammonia within the precursor composition to form ammonium nitrate has been established by chemical analysis and FTIR. The obtained precursor represented an easily dryable and grindable material allowing two modes of combustion: the volume combustion synthesis (VCS) with the using powdered precursor and the self-propagating high-temperature synthesis (SHS) with the using pelletized precursor. The combustion products have been studied by XRD, HR TEM, FTIR, differential dissolution. It was shown that the higher temperature attainable in the self-propagating combustion wave allows this mode to be used for a one-step fabrication of an orthorhombic LaFeO3 with a phase purity of 95%, a crystallite size of 38 nm and a specific surface area of 23 m2/g without the subsequent stage of heat treatment. The redox properties of the synthesized perovskites have been studied by thermal analysis in a soot oxidation reaction. We think that such an approach to perovskite synthesis would provide a universal technique suitable for fabrication of substituted perovskites with a more complex composition.

Figure optionsDownload as PowerPoint slide