Designing the Macroporous Structure of Three-Way Catalyst Particles: The Influence of Template Concentration on Framework Thickness and Mass Transfer

Mass transfer is an essential process that can extendthe performanceand utilization of nanoporous materials in various applications. Therefore,improving mass transfer in nanoporous materials has always attractedmuch interest, and macroporous structures are currently being studiedto enhance mass transfer performance. The introduction of macroporousstructures into three-way catalysts (TWC), which are widely utilizedto control the emission of polluted gases from vehicles, providesthe potential to enhance their mass transfer property and catalyticperformance. However, the formation mechanism of macroporous TWC particleshas not yet been investigated. On the other hand, the influence ofthe framework thickness of the macroporous structure on the mass transferenhancement is still unclear. Therefore, this report investigatesthe particle formation and framework thickness of the macroporousTWC particles synthesized using the template-assisted aerosol process.The formation of macroporous TWC particles was precisely controlledand investigated by altering the size and concentration of the templateparticles. The template concentration played a crucial role in maintainingthe macroporous structure and controlling the framework thicknessbetween the macropores. Based on these results, a theoretical calculationshowing the influence of template concentration on the particle morphologyand framework thickness was developed. The final results showed thatincreasing the template concentration can positively affect the nanoporousmaterial's framework thickness reduction and mass transfercoefficient improvement.