Stages of Catalyst Development

The development of a catalyst up to industrial application involves three stages  

In the research stage, the first step is to formulate the problem. This involves gathering information about market requirements and estimating the value that a particular catalyst system could have at some time in the future. 

Next the concept must be described in chemical terms so that it can be seen whether the project is technically and economically feasible. Estimates must be made whether a profitable yield and selectivity can be achieved, and the raw material supply and future demand for the product must be guaranteed. Only when the results of these estimations are satisfactory can the actual catalyst planning begin. 

If several selective catalysts are initially available, then their suitability and lifetime are intensively investigated in a test reactor known as a pilot plant. The final step is then erection and startup of the industrial plant. Before the actual production in the industrial plant begins, detailed tests are carried out so that any teething problems can be identified right at the beginning and eliminated. 

The time required for the development of a new or an improved catalyst including the trial plant production is quite different. For a substantial improvement of existing 

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Cons This choice may be restricted by technical limitations and, also, by fundamental limitations such as thermodynamic equilibrium, which precludes any ranking of highly performing catalysts under single operating conditions. Other more difficult objective functions like catalyst stability should preferably be assessed at a later stage of catalyst development. 

Metallophosphazenes are a new type of macromolecule designed to bridge the gap between polymers and metals. Although still at an exploratory stage of laboratory development, they may provide access to electronically-conducting polymers, magnetically-active polymers, macromolecular catalysts, electrode mediator systems, or polymers crosslinked by metal atoms. 

It may be of interest to describe the first stages of the development which led to the thorough investigation and to the technical use of these catalysts. 

Due to the frequently observed chemical memory of a working catalyst, reproducible synthesis of the active mass with respect to all synthetic steps is a basic requirement. Moreover, an integrated approach requires the consideration of a catalyst as a hierarchical system taking into account mass transport and thermal conduction properties, as well as mechanical stability in the early stages of the development of synthetic concepts closing the cycle of rational catalyst design. 

There have been some remarkable achievements in catalyst development recognised by numerous Nobel prizes for work done in this area (Box 3) and catalysis has progressed to the stage where it is now difficult to imagine a reaction that cannot be achieved catalytically. However, examination of the catalytic literature shows that the majority of catalysts developed, and many that are in commercial use rely upon the use of metals or other elements whose abundance in the Earth s crust is veiy limited and that are being rapidly consumed. This is illustrated in Figure 1 for papers on asymmetric catalysis published between 1999 and 2005. ... 

The gradual evolution of more reliable supported metal catalysts required reproducible supports. Industrial processes for the production of pure alumina and sihca were soon developed. This led naturally to the control and measurement of chemical and physical properties at all stages of catalyst production to ensure optimum surface area and pore stractrrre. Controls were at first empirical, and quality depended on consistent production conditions. It was not imtil 1938 that techniques for measttring stuface area and pore volume were introduced and modem methods of catalyst qrrality control and characterization began to evolve. ... 

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