Atomic-Scale Mapping of Atomically Dispersed Light-Element Species in Oxide Nanomaterials by Solid-State NMR

Light-element isolated species represent an emerging class of atomically dispersed nanomaterials, yet their precise local and higher-shell coordination environments remain largely inaccessible due to the intrinsic limitations of conventional nanoscale probes. Here, we establish a solid-state NMR method, combining ²³Na and ¹⁷O spectroscopy with first-principles calculations, to directly resolve the atomic-scale structure of light-element isolated species beyond the first coordination shell. Using Na-modified CeO₂ as a representative system, isolated and aggregated sodium species are distinguished by characteristic ²³Na NMR signatures, while ¹⁷O NMR further reveals how light element dopants perturb oxygen coordination across the first to third atomic shells. This approach enables clear differentiation of Na-O-Ce linkages from more remote Na-O-Ce-O environments that are inaccessible to electron microscopy and X-ray-based techniques. As a demonstration of atomic-scale structure-adsorption correlation, CO₂ is shown to preferentially adsorb at Na-O-Ce sites rather than at Na-O-H groups.