Synthesis and characterization of nickel ferrite nanocatalysts for CO 2 decomposition

Abstract

The decomposition of CO 2 over oxygen deficient nickel ferrite nanoparticles (NFNs) at 573 K was studied and fine structures of Fe/Ni species in NFNs catalysts were investigated. Oxygen deficiency of NFNs was obtained by reduction in hydrogen. Decomposition of CO 2 into C and O 2 was carried out within few minutes when it comes into contact with oxygen deficient NFNs through incorporation of O 2 into NFNs. Oxygen and carbon rather than CO were produced in the decomposition process. The complete decomposition of CO 2 was possible because of higher degree of oxygen deficiency and surface-to-volume ratio of NFNs. The pre-edge XANES spectra of Fe atom in NFNs exhibits an absorbance feature at 7115 eV for the 1 s to 3 d transition which is forbidden by the selection rule in case of perfect octahedral symmetry. The EXAFS data showed that the NFNs had two central Fe atoms coordinated by primarily Fe–O and Fe–Fe with bond distances of 1.87 and 3.05 Å, respectively. Methane gas was produced during the reactivation of NFNs by flowing H 2. Decomposition of CO 2, moreover, recovery of valuable CH 4 using heat energy of offgas produced from power generation plant or steel industry is an appealing alternative for energy recovery.