Dynamics of strong metal-support interactions: Investigating Pt and Pt-based alloys on CdS nanorods through experimental and simulated approaches

The catalytic performance of supported metal nanoparticles (NPs) is greatly affected by metal-support interaction (MSI). Understanding the mechanisms and dynamics of MSI in heterogeneous catalysis remains challenging. Traditionally, MSI studies have focused on metal oxide supports and rarely compared MSI between Pt and Pt-based alloys, despite the importance of Pt in catalysis. In this study, we introduce CdS nanorods as a novel support material and investigate the MSI behavior of both Pt and Pt-based alloy NPs using in situ TEM electron beam irradiation. Our findings show that Pt NPs have strong MSI with CdS and that encapsulation layers form over Pt NPs because Pt has the high surface energy. On the other hand, Pt-based alloys have weaker MSI. These experiments were validated by direct thermal annealing for four hours. Molecular dynamics simulations were used to explain the observed behavior, providing insights into how the surface energy differences between Pt and Pt-based alloys influence their interactions with CdS nanorods. These findings offer valuable insights into catalyst design, highlighting the potential for controlling MSI strength to optimize catalytic performance in heterogeneous systems.