Probing the Local Structure of Na in NaNO₃-Promoted, MgO-Based CO₂ Sorbents via X-ray Absorption Spectroscopy.

ABSTRACT: This work provides insight into the local structure of Na in MgO-based CO₂ sorbents that are promoted with NaNO₃. To this end, we use X-ray absorption spectroscopy (XAS) at the Na K-edge to interrogate the local structure of Na during the CO₂ capture (MgO + CO₂ ↔ MgCO₃). The analysis of Na K-edge XAS data shows that the local environment of Na is altered upon MgO carbonation when compared to that of NaNO₃ in the as-prepared sorbent. We attribute the changes observed in the carbonated sorbent to an alteration in the local structure of Na at the NaNO₃/MgCO₃ interfaces and/or in the vicinity of [Mg²⁺···CO₃^2-] ionic pairs that are trapped in the cooled NaNO₃ melt.

SUBMITTER: Rekhtina M 

PROVIDER: S-EPMC10720340 | biostudies-literature | 2023 Dec

REPOSITORIES: biostudies-literature