Catalysis of Organic..

310 Catalyst Library DesignD in compositions with high activity (see the area between the two lines in theright-side hologram).• When the concentration of component D is low A has a definite negative effect onthe activity (see left-side hologram).• When the amount of D is low the activity is diminishing upon increasing theamount of A (see line 1a). The circle shows the area of high activity at low Acontent.• At high concentration of C upon increasing the concentration of B the highactivity areas are shifted to areas with low D content (see lines at the right-sidehologram). It means that the addition of component C replaces component D.These results show that HRS possesses an excellent visualization ability. Thevisualization allows us to elucidate the influence of all components on the activity.The results show that similar activity ranges can be obtained in differentcompositional areas. Consequently, in this case the difference in the price ofcomponents can be taken into account before using a given catalyst in the production.Catalyst and Process OptimizationCatalyst library design is considered as an optimization procedure in a multidimensionalexperimental space. The variables in the multi-dimensional space can bedifferentiated as follows: (i) compositional variables, and (ii) process variables. Theterm compositional variables have already been discussed.The most common process variables are as follows: temperature, pressure,concentrations, pH, catalyst pore size, flow rate, stirring rate, etc. In the process ofcreating a compositional catalyst library the initial steps are as follows:1. Selection of the components,2. Choosing the concentration levels of components,3. Introduction of a limit for a given component (Pt max = 3 wt%),4. Introduction of a limit for the total amount of components (total metal content= 5 wt. %).For catalysts used in fine chemistry the following approaches can be combined inthe catalyst library design and process optimization:1. Preparation of multi-component modified catalysts;2. Creation of an optimum composition of modifiers (promoters, inhibitors,selective poisons, etc.);3. Creation of a multi-dimensional experimental space containing alsoprocess variables (pressure, temperature, pH, flow rate, etc.)