The ease of separation of heterogeneous catalysts from the reaction environment makes them an essential component of simplified less energy intensive processes. Furthermore, newly designed catalytic systems can exhibit substantial longevity, when regenerated appropriately. These features make heterogeneous catalysis an integral part of the current industrial landscape and critical to efforts towards a more sustainable future. Metal supported catalysts such as platinum, rhenium and tin on supports such as silica, alumina, silica-alumina and carbon are currently used to produce hydrogen and a wide range of aromatics and olefins. Acid catalysts such as zeolites are used in significant volume to convert large hydrocarbons to gasoline and diesel fuel in fluid catalytic cracking (FCC) units.
In simple terms a heterogeneous reaction involves the transport of reactant molecules to the reaction site, molecular interactions with an active site, and the subsequent release of products. The active surface area of a metal supported catalyst and the porous structure of the associated support both have a significant influence on production rates, selectivity and lifetime. Designing a catalyst with a suitable pore size allows reactant molecules of the desired size to enter and products of the reaction to leave the catalyst without diffusive limitation, enabling precise control of concentration profiles around the catalytic site. This is critical for creating a selective catalyst. However, optimization of the system relies equally on quantifying and optimizing the strength of chemical interactions between the active catalytic site and reactants/products.
Heterogeneous catalyst characterization is a core area of expertise for Micromeritics and the company offers an integrated range of analytical solutions of unsurpassed breadth and depth. This range includes systems for:
- Gas adsorption – for measuring surface area and porosity.
- Chemisorption – for active site characterization
- Particle size testing
- Porosity and density measurement
- Zeta potential testing
- Flowability characterization
- Temperature programmed analyses including ammonia and amine analyses for FCC catalysts. (e.g. temperature programmed reduction, temperature programmed oxidation, temperature programmed desorption, temperature programmed decomposition.)
- Catalyst screening
- Pilot scale units for scale-up studies
These systems provide researchers and developers with the information needed to accelerate catalysts to commercialize use, to qualify catalyst vendors and to optimize regeneration strategies. More specifically they:
- Enable detailed characterization of the physical texture and internal structure of the catalyst, for precise control of the localized reaction environment.
- Quantify key catalyst parameters such as metal surface area, metal dispersion, average crystallite size, supporting knowledge-led optimization of the active site.
- Measure catalyst behavior under oxidizing and reducing conditions as required, to fully scope performance.
- Allow the detailed investigation of catalyst lifetime to support the development of sound reactivation vs. replacement strategies
- Screen catalysts under industrially relevant conditions to generate defining parameters such as turn over frequency and to representatively scope reactivity, selectivity, lifetime and regeneration strategies, with minimum quantities of catalyst.