An autocatalytic tin plating bath containing Sn2+ ions, Ti3+ ions as reducing agent, an organic complexing agent and phenanthroline or a derivative thereof as stabilizing agent is disclosed.

The catalysts comprise a DMC compound, an organic complexing agent, and from about 2 to about 80 wt.% of a functionalized polymer or a water-soluble salt derived from the polymer.

At least one step of the bleaching process comprises treating the lignocellulose material with a peroxide-containing bleaching agent at a pH of-2 to 7 in the presence of 0.01 -5 g/l of an organic or inorganic complexing agent.

Such complexing agent preferably possesses one or more amino group in addition to other groups with unshared electrons such as hydroxyl, carbonyl, amido, ester and alkoxyl groups in the same molecule.

The catalysts comprise a DMC complex, and organic complexing agent, and from about 5 to about 80 wt.%, based on the amount of catalyst, of a polyether having a number average molecular weight less than about 500.