DEVELOPMENT OF A GENETIC ALGORITHM FOR MOLECULAR SCALE CATALYST DESIGN

A genetic algorithm has been developed to determine the optimal design of a two-component catalyst for the diffusion-limited A + B --> AB up arrow reaction in which each species is adsorbed specifically on one of two types of sites. Optimisation of the distribution of catalytic s ites on the surface is achieved by means of an evolutionary algorithm which repeatedly selects the more active surfaces from a population of possible solutions leading to a gradual improvement in the activity o f the catalyst surface. A Monte Carlo simulation is used to determine the activity of each of the catalyst surfaces. It is found that for a reacting mixture composed of equal amounts of each component the optim al active site distribution is that of a checkerboard, this solution b eing approximately 25% more active than a random site distribution. St udy of a range of reactant compositions has shown the optimal distribu tion of catalytically active sites to be dependent on the composition of the ratio of A to B in the reacting mixture. The potential for appl ication of the optimisation method introduced here to other catalysts systems is discussed. (C) 1997 Academic Press.