Site and shape dependence of N-ethylcarbazole (NEC) dehydrogenation on platinum nanoparticles

Liquid organic hydrogen carriers (LOHCs) require catalysts that extract H rapidly while allowing the carrier to leave the surface. We solvent-explicit molecular dynamics to quantify how Platinum nanoparticle shape and site type control N-ethylcarbazole (NEC) dehydrogenation. We modeled Pt nanoparticles that expose the (111) and (100) faces with low-coordination edges and vertices; a 4.63 nm cuboctahedron nanoparticle surrounded in an explicit NEC liquid containing 1,100 molecules is the benchmark system. For NEC states from fully hydrogenated to fully dehydrogenated, we run 100-ns trajectories and calculate residence-time distributions τ, dissociation constants K_D, and adsorption free energies ΔG_ads for each site. Edges and vertices are the dominant hydrogen-abstraction regions, while NEC occupancy is higher on terraces. As NEC approaches 0H, terrace residence increases, and desorption competes with further reaction due to stronger aromatic ring–Pt binding interactions. Nanoparticle shapes that maximize low-coordination sites while avoiding terrace crowding yield better overall kinetics according to τ, K_D, and ΔG_ads trends.