Ni-based A~2BO~4-type mixed oxide, La~2NiO~4, was prepared by means of a citric acid complexing method. X-ray diffraction pattern identified it as a single phase with a tetragonal K~2NiF~4 structure in which Ni^2^+ and La^3^+ ions were evenly distributed. It also indicated the nickel existed mainly as Ni^0 after reducing. Rare earth oxides, La~2O~3, could prevent transition metal from agglomerating and promote dispersion of nanoscale Ni^0 particles, which was very advantageous for carbon nanotube growth. A large amount of carbon nanotubes from catalytic decomposition of CH~4 and disproportionation of CO were obtained using La~2NiO~4 oxides as catalyst precursor. The morphology of the carbon nanotubes was examined by transmission electron microscopy(TEM) and scanning electron microscopy (SEM). High resolution transmission electron microscopy image and Raman spectrum of carbon nanotubes showed they were multi-walled nanotubes with a higher degree of graphitization.

Key words: NICKEL OXIDE, LANTHANUM OXIDE, METHANE, CARBON MONOXIDE, CATALYST, X-RAY DIFFRACTION ANALYSIS, TRANSMISSION ELECTRON MICROSCOPY, SCANNING ELECTRON MICROSCOPES