The invention concerns recyclable solid oxidation catalysts comprising a metal compound of a pentavalent or hexavalent metal M and selected among the group consisting of tantalum, vanadium, niobium, chromium, molybdenum, tungsten, grafted at the surface of a solid oxide with at least one, preferably one, covalent bond between an oxygen atom of the solid oxide and the metal M atom, the grafted metal compound having at least two alkoxy groups bound to the metal by the oxygen atom. Preferably, at least 2 alkoxy groups bound to the metal M belong to a polyol unit, preferably diol. The invention also concerns oxidation methods, in particular epoxidation methods using same.