We describe the issues of evolutionary library design in the frame of Material and Catalyst discovery. Concepts of diversity management on material library to enhance the efficiency of the optimization are proposed. The diversity monitoring is implemented by two different approaches. The first deals with a dynamic monitoring of mutation and crossover rates whereas the second involves a selection step based on sample "distance''. Simulations of optimization are performed on a surface response which is designed to mimic realistic data. Algorithm performances are compared in terms of both efficiency and reliability. (C) 2007 Elsevier B.V. All rights reserved.