Design and application of transition metal catalysts for laundry bleach

Abstract

Hydrogen peroxide based bleach reactions are increasingly important for many applications such as pulp and paper bleach, pre-treatment of cotton, waste water treatment and laundry. The search of catalysts being able to effectively activate peroxide in these applications has been a major field of research for some time. With respect to the laundry process, transition metal based catalysts are expected to increase the activity at low temperatures for the bleaching of stains or the inhibition of dye transfer, while retaining a low level of textile dye and fiber damage. We review herein major aspects of our research in this field for manganese and iron complexes of different ligand systems. Catalyst design principles are summarized and discussed to illustrate the effective development of catalysts meeting the requirements of the laundry application. Results of model experiments are correlated with application properties in order to improve the understanding of the catalytic bleach process.