Mapping the oxygen structure of γ-Al<sub>2</sub>O<sub>3</sub> by high-field solid-state NMR spectroscopy.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 32680993.
- Also identified by DOI 10.1038/s41467-020-17470-4 and PMC identifier 7367832.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
γ-Al<sub>2</sub>O<sub>3</sub> is one of the most widely used catalysts or catalyst supports in numerous industrial catalytic processes. Understanding the structure of γ-Al<sub>2</sub>O<sub>3</sub> is essential to tuning its physicochemical property, which still remains a great challenge. We report a strategy for the observation and determination of oxygen structure of γ-Al<sub>2</sub>O<sub>3</sub> by using two-dimensional (2D) solid-state NMR spectroscopy at high field. 2D <sup>17</sup>O double-quantum single-quantum homonuclear correlation NMR experiment is conducted at an ultra-high magnetic field of 35.2 T to reveal the spatial proximities between different oxygen species from the bulk to surface. Furthermore, 2D proton-detected <sup>1</sup>H-<sup>17</sup>O heteronuclear correlation NMR experiments allow for a rapid identification and differentiation of surface hydroxyl groups and (sub-)surface oxygen species. Our experimental results demonstrate a non-random distribution of oxygen species in γ-Al<sub>2</sub>O<sub>3</sub>.