The chemical reactivity of the uranium oxide prepared by thermal denitration is not as good as that of the ADU precipitation route due to lower specific surface area (SSA) of the former. In the present study, the chemical reactivity of the above uranium oxide towards hydro-fluorination has been enhanced by employing a reduction-oxidation–reduction cycle. This resulted in an increase in the SSA from 0.24 to 2.35 m²/g leading to enhanced reactivity towards hydro-fluorination. The oxides at each step were characterized for particle size, SSA, phase, crystallite size and morphology. The mechanism behind the increase in specific surface area was investigated through morphological analysis of the oxides at each step of the process by FESEM and a physical model was proposed for the same.