No abstract

Once an active species and perhaps its support have been selected, the task is to construct from precursors of these active species a catalytic structure whose properties and characteristics will meet the demands of an industrial user. One must avoid creating a structure that is only a laboratory curiosity which for technical or economic reasons can not be manufactured on industrial scale. Properties and Characteristics of Industrial CatalystsIn addition to the fundamental properties that come from the very definition of a catalyst, i.e., activity, selectivity, and stability, industrial applications require that a catalyst be regenerable, reproducible, mechanically and thermally stable, original, economical, and possess suitable morphological characteristics. ActivityA high activity will be reflected either in high productivity from relatively small reactors and catalyst volumes or in mild operating conditions, particularly temperature, that enhance selectivity and stability if the thermodynamics is more favorable. SelectivityHigh selectivity produces high yields of a desired product while suppressing undesirable competitive and consecutive reactions. This means that the texture of the catalyst (in particular pore volume and pore distribution) should be improved toward reducing limitations by internal diffusion, which in the case of consecutive reactions rapidly reduces selectivity.