In this manuscript, ruthenium (Ru) nanoparticles functionalized with nitrene ligands through the ruthenium-nitrene (Ru=N) pi bonds are explored. By synthesizing the nitrene ligands with and without N-15-labelling, Ru=N it bonds on Ru nanoparticles are evidenced by experimental and theoretically calculated FTIR spectra. The coordination of nitrene ligands on Ru nanoparticles surface, the interfacial charge delocalization and the impact of nitrene ligands on the catalytic performance of Ru nanoparticles are further characterized by magic-angle spinning solid-state carbon nuclear magnetic resonance spectroscopy (C-13 NMR) of (CO)-C-13-adsorbed Ru nanoparticles, photoluminescence and the hydrogenation of styrene. (C) 2020 Elsevier Inc. All rights reserved.