Identification of CO2 adsorption sites on MgO nanosheets by solid-state nuclear magnetic resonance spectroscopy

• Published in: Nature communications Vol. 13; no. 1; pp. 707 - 6
• Main Authors: Du, Jia-Huan, Chen, Lu, Zhang, Bing, Chen, Kuizhi, Wang, Meng, Wang, Yang, Hung, Ivan, Gan, Zhehong, Wu, Xin-Ping, Gong, Xue-Qing, Peng, Luming
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 04-02-2022; Nature Publishing Group; Nature Portfolio
• Subjects: 119/118; 140/131; 147/143; 639/301/299; 639/638/440; 639/638/542/971; 639/925/930/878/1264; Adsorption; Binding sites; Carbon dioxide; Density functional theory; Experimental methods; Humanities and Social Sciences; Magnesium oxide; Magnetic resonance spectroscopy; multidisciplinary; Nanomaterials; Nanosheets; Nanotechnology; NMR; NMR spectroscopy; Nuclear magnetic resonance; Oxygen; Oxygen ions; Resonance; Science; Science (multidisciplinary); Solid state; Spectroscopy; Spectrum analysis; Structural analysis; Surface chemistry; Surface structure
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-022-28405-6

The detailed information on the surface structure and binding sites of oxide nanomaterials is crucial to understand the adsorption and catalytic processes and thus the key to develop better materials for related applications. However, experimental methods to reveal this information remain scarce. Here we show that
17
O solid-state nuclear magnetic resonance (NMR) spectroscopy can be used to identify specific surface sites active for CO
2
adsorption on MgO nanosheets. Two 3-coordinated bare surface oxygen sites, resonating at 39 and 42 ppm, are observed, but only the latter is involved in CO
2
adsorption. Double resonance NMR and density functional theory (DFT) calculations results prove that the difference between the two species is the close proximity to H, and CO
2
does not bind to the oxygen ions with a shorter O···H distance of approx. 3.0 Å. Extensions of this approach to explore adsorption processes on other oxide materials can be readily envisaged.
The characterization of the surface structure and binding sites of materials is crucial for designing advanced materials for adsorption processes. Here, the authors use
17
O solid-state nuclear magnetic resonance spectroscopy to identify specific CO
2
adsorption sites on MgO nanosheets.