Formulation of the forming paste for preparing unsupported granulated triuranium octoxide U₃O₈ was developed. The mixture contains U₃O₈ and (NH₄)₂U₂O₇ in a weight ratio from 1: 1 to 1: 1.5, and also water in an amount of 25–40 wt % relative to the sum of the dry components. Calcination of crude granules at 800–1100°С results in formation of strong ceramic granules with 57–45% open porosity, consisting of U₃O₈. Granulated U₃O₈ efficiently catalyzes the conversion of ammonium nitrate to nitrogen in an NH₄NO₃–H₂O vapor–gas mixture with the addition of ammonium carbonate. The absence of support makes the catalyst composition more definite and simplifies its regeneration.