Method for catalytic oxidation of cellulose and method for making a cellulose product

A method for catalytic oxidation of cellulose using a heterocyclic nitroxyl radical as catalyst, main oxidant acting as oxygen source, and an activator of the heterocyclic nitroxyl radical, characterized in that the method comprises

• (a) a separate preliminary activation step of the heterocyclic nitroxyl radical consisting of activating the heterocyclic nitroxyl radical catalyst with hypochlorite in a reaction medium in the absence of cellulose and adjusting the pH with an acid to a pH of 6 to 8;
• and
• (b) a cellulose oxidation step using the activated catalyst and main oxidant to oxidize primary hydroxyl groups of cellulose in a reaction medium comprising the activated heterocyclic nitroxyl catalyst, cellulose, and main oxidant at a pH higher than the pH of the preliminary activation step;
• and
• wherein hypochlorite is used as the main oxidant in the cellulose oxidation step.