(638b) Understanding the Active Facet and Particle Size-Dependent Activity Trends for Phenol Hydrogenation on Pt and Rh Nanoparticles
AIChE Annual Meeting
Monday, November 15, 2021 - 8:00am to 8:20am
In this work, we study ECH and TCH of phenol, a model bio-oil compound, on Pt and Rh NPs supported on carbon (Pt/C and Rh/C) to identify the active site on Rh/C and explain the activity of Rh/C and Pt/C. We fit phenol TCH rate data on Rh/C to a Langmuir-Hinshelwood model and extract the phenol adsorption energy on the active site to compare with adsorption energies previously measured on terraces and stepped facets. We model phenol hydrogenation on (111) terraces and (221) steps of Pt and Rh using density functional theory and microkinetic modeling to elucidate the relationship between intrinsic kinetics and phenol adsorption strength. We study phenol ECH on Rh/C as a function of particle size and find that larger particles, which have a higher fraction of terrace sites compared to smaller particles, are more active. Ultimately, we find that the (111) terraces of Pt and Rh are active for phenol hydrogenation, which our computational results indicate is due to higher intrinsic activity and weaker phenol adsorption. By providing a better understanding of the active site of Pt/C and Rh/C for phenol hydrogenation, these findings may inform catalyst design.