# A Combined Neutron and Synchrotron X‑ray Scattering Study of a MgAl-Layered Double Oxide

## TL;DR

This study uses advanced scattering techniques to investigate the structure of a magnesium-aluminum oxide material after thermal treatment.

## Contribution

The paper presents a novel structural model of a MgAl-layered double oxide using combined neutron and X-ray scattering.

## Key findings

- The structure of AMO-Mg2.33Al LDO is consistent with a modified rock salt structure.
- The material contains octahedrally coordinated layers with vacancies and tetrahedrally coordinated Al3+ sites.

## Abstract

Owing to their vast chemical and structural flexibility,
layered
double hydroxides (LDHs) are among some of the most promising materials
for many catalytic applications. Thermal decomposition below 700 °C
leads to the formation of a complex semiamorphous mixed metal oxide
(LDO). In this study, the product of calcination of aqueous miscible
organic solvent-treated AMO-[Mg0.70Al0.30(OH)2]­(CO3)0.15·yH2O·zEtOH at 600 °C (AMO-Mg2.33Al LDO) has been investigated using a synergistic combination of
high-resolution synchrotron X-ray and neutron scattering techniques,
as well as high-angle annular dark-field scanning transmission electron
microscopy (HAADF-STEM), solid-state NMR (ssNMR), and thermogravimetric
analysis coupled with mass spectrometry (TGA-MS). The local and extended
structure of AMO-Mg2.33Al LDO has been modeled by reciprocal
and real space X-ray and neutron scattering analyses and is consistent
with a modified rock salt structure consisting of octahedrally coordinated
layers containing a small number of vacancies and the tetrahedrally
coordinated Al3+ sites in contrast to previous reports.