Reactivation of a hydrogenation catalyst

A process for the reactivation of an anthraquinone hydrogenation catalyst in the preparation of hydrogen peroxide, comprising at least the following successive stages:

• a) optional washing of the catalyst to be reactivated,
• b) optional drying or draining of the catalyst to be reactivated,
• c) reactivation of the catalyst to be reactivated by bringing said catalyst into contact with an aqueous solution comprising from 0.01% to 1%, of ammonia, by weight, limits included,
• d) optional washing of the reactivated catalyst, and
• e) drying or draining of said reactivated catalyst resulting from stage c) or from stage d).