Illuminating the Impact of Hydrocarbon Adsorption on Ru Surface Energetics

Chemical recycling of plastic waste through hydrogenolysis using Ru/Al₂O₃ catalysts offers a promising route to sustainable energy infrastructure by producing high-value products. However, the control of product distributions remains challenging due to the elusive nature of polymer adsorption on catalyst surfaces. This study explores the complex interactions between polymers and Ru/Al₂O₃catalysts, which involve solid reactants and oil, liquid, and gas products under relatively high temperature and hydrogen pressure conditions. Our findings reveal a structural hysteresis associated with the adsorption of various hydrocarbons, indicating that polymer adsorption significantly impacts the Ru metal structure at the catalyst interface. We compare real and model systems under relevant conditions by extracting the mean-square displacement of both Ru/Al₂O₃ catalysts and single crystal Ru. This work aims to elucidate the fundamental phenomena governing polymer-catalyst interactions, ultimately guiding the design of more robust catalysts with extended lifetimes and improved performance for sustainable plastic recycling processes.