Fine control of catalyst structure: improved catalyst performance by tuning the active site location

In order to improve existing and develop novel industrial catalytic processes, tailored catalysts are needed for a number of chemical reactions. Rational catalyst design and optimization must be advanced beyond their current abilities based on sound scientific knowledge about phenomena underlying catalysis. Heterogeneous catalytic processes are most often optimized by determining the optimum temperature, pressure, and composition of the reaction mixture. The distribution of active material inside the solid catalyst particles is an additional variable in the design of optimal catalysts. Uniform composition and even spreading of active sites on catalyst pellets seldom is the optimum configuration. The aim of the project is to obtain an experimental descriptor for the intrinsic activity of the active site and its utilization. The latter will assist the catalyst development process to attain a previously unachieved level of understanding of reactivity trends through deconvolution of site density and intrinsic activity. In this project we consider the problem of computing the effective performance of a catalyst under diffusion-limited conditions, given a particular spatial arrangement of catalytically active sites on the catalyst surface for monofunctional and bifunctional catalysts. Two reactions will be investigated: CO oxidation over a monofunctional Pt catalyst and n-Hexane hydrocracking using a bifunctional catalyst, containing metal next to acid sites.