Synthesis of MgNi2O3 and kinetics of thermal decomposition of the oxalate precursor

✍ Scribed by Lin Chuanming; Chen Donghua; Tang Wanjun; Peng Yuhua

• Publisher: Elsevier Science
• Year: 2006
• Tongue: English
• Weight: 148 KB
• Volume: 75
• Category: Article
• ISSN: 0165-2370
• DOI: 10.1016/j.jaap.2005.06.007

✦ Synopsis

The thermal decomposition processes taking place in the solid state mixture of NiC 2 O 4 Á2H 2 O-MgC 2 O 4 Á2H 2 O (2:1 mole ratio) have been investigated in air using TG-DTG, differential scanning calorimetry (DSC) and XRD techniques. The decomposition proceeded through four well-defined steps while TG curves closely corresponded to the theoretical mass loss. The result of XRD showed the well-crystallized MgNi 2 O 3 formed in the sample calcined at 600 8C for 2 h. The activation energies for the decompositions of NiC 2 O 4 and MgC 2 O 4 were calculated through the Ozawa and Kissinger-Akahira-Sunose (KAS) methods, and the possible conversion functions have been estimated through the comparative method. The activation energies for the decompositions of NiC 2 O 4 were 151.05 kJ/mol (KAS method) and 152.6 kJ/ mol (Ozawa method), and the activation energies for the decompositions of MgC 2 O 4 were 204.74 kJ/mol (KAS method) and 205.72 kJ/mol (Ozawa method). The possible conversion function for the decomposition of NiC 2 O 4 and MgC 2 O 4 kept to the conversion function of ''Nucleation and Growth'' and ''phase boundary reaction'', respectively.