Analysis of the Concentrations of Surface Ni Ions in Ni/CeO2 With 17O Solid-State NMR Spectroscopy

With Ni/CeO2 as an example, which has important applications in catalysis, 17O solid-state nuclear magnetic resonance (NMR) spectroscopy was applied to explore and analyze the concentration of surface Ni ions, according to the changes in the 17O NMR intensity of surface oxygen ions. The results indicate that the Ni concentrations in the first and second top metal ion layers in 10% NiCe-500 and 20% NiCe-300 are within the ranges of 9%~17% and 8%~15%, respectively. This approach may be extended to study the concentration of the doped paramagnetic elements in the surface for a variety of doped oxide materials.