Exploring the impact of separation wall characteristics on Pt particle sintering inhibition: A theoretical study

The performance of supported metal catalysts often diminishes significantly due to the sintering of metal particles. This study investigates the impact of separation wall characteristics on the sintering behavior of TiO2-supported Pt particles, aiming to enhance catalyst stability. We developed a machine learning potential for the Pt-TiO2 system, achieving computational accuracy comparable to first-principles. Using molecular dynamics simulations, we explored how the height, width, and length of separation walls influence Pt particle sintering. Our results show that increasing the height and width of separation walls effectively inhibits sintering through distinct mechanisms. Increased height primarily acts as a physical barrier, while increased width creates an energy "valley" that anchors Pt particles, indirectly increasing inter-particle distances and thus reducing sintering. Additionally, we examined the impact of Pt particle diameter, finding that a wall height-to-diameter ratio between 0.36 and 0.57 effectively mitigates sintering. We also observed that excessively tall walls may overly attract Pt particles, altering their shape, whereas wider walls do not have this effect. This study provides theoretical insights and design guidelines for optimizing the anti-sintering performance of supported metal catalysts, crucial for improving their catalytic efficiency and longevity.