A new application note on the Malvern Instruments’ website discusses the criticality of particle size in the development and production of heterogeneous catalyst materials, and presents data to demonstrate the utility of the Mastersizer 3000 particle size analyser in achieving optimum reactivity.
Not only does the Mastersizer 3000 accurately determine particle size distribution for a wide range of catalyst materials, it also uses the laser diffraction measurement to calculate specific surface area. And uniquely it offers the ability to predict attrition rate in a fluidised bed from dry powder measurements at different pressures.
Heterogeneous describes a catalyst that is present in one phase (a solid) with the reactants in another (liquid or gas). For this type of catalyst, the reaction rate depends on the specific surface area of the solid material as this defines the available contact area between catalyst and reactants. Decreasing the particle size of a catalyst in order to increase specific surface area is often a beneficial strategy for improving its reactivity. However, a smaller particle size can be problematic. In some reactions a catalyst with particles that are too fine can cause a number of problems, ranging from health and safety issues due to dust formation through to loss of reactivity through uncontrolled agglomeration. Balancing the efficacy of the catalyst with reducing any risks of having a small particle size means that there is usually an optimum particle size range for a given catalyst.
The Mastersizer 3000 laser diffraction particle size analyser delivers rapid, accurate particle size distributions for both wet and dry dispersions with the minimum of effort, bringing operator-independent measurements that every user can rely on. It measures over a wide dynamic range from 0.01 - 3500µm and packs this exceptional performance into the smallest of footprints. Of particular value for the study of catalyst attrition is the power and precision of the integral Aero dry dispersion engine which enables very close control of the dispersion conditions applied. This enables researchers to gain real insight into the propensity of different catalysts to break down during processing.
