COMPUTER-AIDED CATALYST DESIGN

Time-saving catalyst development by computer-aided catalyst design. 

This example of side-chain alkylation of toluene with methanol serves not only to demonstrate the interaction between basic and acidic centers in a zeolite but also to illustrate another type of zeolite catalysis or of catalysis in general. The key phrases "computer graphics" or "computer-aided catalyst design" are used to describe this novel catalyst research. With the aid of computer graphics, it is possible to simulate zeolite structures and produce images of these structures. Computer graphics can also be used to produce pictures of molecules such as toluene in the zeolite pores or cages. 

The computer image allows us to model complicated processes and visualize them in graphic form, to extend our range of ideas. Finally, "computer-aided catalyst design" facilitates the choice of suitable catalysts and reduces the number of experiments. Because of the well defined structure and the available structural data, this type of catalyst development is more promising for zeolite catalysts than for conventional catalysts. 

Catalyst A Computer-Aided Drug Design System Specifically Designed for Medicinal Chemists. 

Computer-aided molecular design methods are well suited to modelling reaction pathways, including transition states. These methods can aid significantly not only in the understanding of current catalytic processes but also in the design and identification of new catalysts and even new classes of catalysts. 

Transition metal catalysts play a crucial role in many industrial applications, including the manufacture of lubricants, smoke suppressants, corrosion inhibitors and pigments. The development of novel catalysts is commonly performed using a trial-and-error approach which is costly and time-consuming. The application of computer-aided molecular design... 

Some studies of potential commercial significance have been made. For instance, deposition of catalyst some distance away from the pore mouth extends the catalyst s hfe when pore mouth deactivation occui s. Oxidation of CO in automobile exhausts is sensitive to the catalyst profile. For oxidation of propane the activity is eggshell > uniform > egg white. Nonuniform distributions have been found superior for hydrodemetaUation of petroleum and hydrodesulfuriza-tion with molybdenum and cobalt sulfides. Whether any commercial processes with programmed pore distribution of catalysts are actually in use is not mentioned in the recent extensive review of GavriUidis et al. (in Becker and Pereira, eds., Computer-Aided Design of Catalysts, Dekker, 1993, pp. 137-198), with the exception of monohthic automobile exhaust cleanup where the catalyst may be deposited some distance from the mouth of the pore and where perhaps a 25-percent longer life thereby may be attained. 

At present, according to the review of Tsotsis et al. (in Becker and Pereira, eds., Computer-Aided Design of Catalysts, Dekker, 1993, pp. 471-551), there is no record of industrial implementation of reac-tors with catalytic membranes. 

Becker, E.R., and C.J. Periera, ed.. Computer Aided Design of Catalysts, Marcel Dekker, New York. 

Computer-Aided Design of Catalysts, edited by E. Robert Becker and Carmo J. Pereira... 

Species concentration Capillary number Concentration of species a Computer aided design Concentration of species b Charge-coupled device Eluid specific heat Computational fluid dynamics Constrained-geometry catalyst Concentration at node i Concentration of species i Elux limiter Specific heat... 

Iglesia, E., Reyes, S.C., and Soled, S.L. 1993. Computer-aided design of catalysts, ed. R.E. Becker and C.J Pereira. New York Marcel Dekker. 

The above achievements depend highly on both the recent advances in rational catalyst design with the aid of computational science represented by DFT calculations and the wide range of catalyst design possibilities that are afforded by FI catalysts. These possibilities are derived from the readily varied steric and electronic properties of the phenoxy-imine ligands. It is expected that future research on FI catalysts will provide opportunities to produce additional polyolefin-based materials with unique microstructures and a chance to study catalysis and mechanisms for olefin polymerization. 

Gavriilidis, A. Varma, A. Morbidelli, M. In Computer Aided Design of Catalysts and Reactors Pereira, C. J. Becker, E. R., Eds. Chemical Industries Series Marcel-Dekker, in press. 

A. M. Champagnie, et al., Catalytic membrane reactors, in Computer aided design of catalysts, Eds. E. R. Becker,... 

---