Many substances act as catalysts, for example platinum silver and oxides such as vanadium pentoxide.
The application of catalysts in industry is enormous. One of the first uses of a catalyst was the use of iron ore magnetite to combine hydrogen and nitrogen to produce ammonia on an economical scale. The addition of this catalyst meant that hydrogen and nitrogen could now be combined using less energy than before, which in turn led to the process of an economic product. Since the catalyst does not take part in the chemical reaction, it is only the surface area that does the work in speeding up the reaction. It is therefore important to expose as much of the surface area as possible, especially with precious metals such as platinum.