Structure Sensitivity,\nMagnetization, and Topological\nAnalysis in DFT Models of Ni Nanoparticles and Surfaces Functionalized\nby Adsorbed Trimethylphosphine

Functionalizing\nnickel nanoparticles with ligands, such as phosphines,\ncan enhance their catalytic performance. However, the ligand effects\nare poorly known at the molecular level. In this work, the adsorption\nproperties of trimethylphosphine (PMe<sub>3</sub>) on Ni nanoparticles\n(NPs) and extended surfaces were investigated via spin-polarized dispersion-corrected\ndensity functional theory calculations. The coverage effect of phosphine\nwas explored by considering monoadsorption and monoshells on NPs and\nvarious adlayers from low coverage to saturation on surfaces. Icosahedral,\nino-decahedral, cuboctahedral, truncated octahedral, and Marks-decahedral\nNi nanoclusters at a size of 146–147 atoms were compared to\nthe Ni(111), (100), and (110) surfaces. PMe<sub>3</sub> strongly adsorbs\non Ni surfaces and NPs, with a clear preference for the icosahedron.\nThe chemisorption on extended surfaces is globally stronger than the\nadsorption on NPs, demonstrating the necessity of describing NPs by\nexplicit models. The topological analysis shows the formation of a\nNi–P covalent dative bond with a net electronic donation from\nphosphorus to nickel. The presence of strongly chemisorbed PMe<sub>3</sub> weakens the total Ni magnetization by specifically quenching\nthe spin polarization at Ni atoms bound to ligands. Our results invite\nthe scientific community to explore the stability and reactivity of\nother phosphine ligands on metallic nanoparticles.