The hydration of [Mg2Al(OH)6]+[Cl–, yH2O]
LDH was
investigated by volumetric water adsorption, X-ray diffraction, Fourier
Transformed Infrared (FTIR) sepctroscopy, and Near Ambient Pressure
X-ray Photoelectron Spectroscopy (NAP-XPS). It was demonstrated that
water uptake into interlayer region can be quantified by NAP-XPS.
The LDH’s electronic structure is assessed for increasing relative
humidity (RH) up to 0.044. The Cl 2p level appears
essentially unaffected by water uptake, but as supported by DFT calculation,
H-bonds between chloride and water induce Cl 3p orbitals splitting.
At RH = 0.7, LDH is covered by a water film that
contains Mg and Cl species but no Al. Soft X-ray radiolysis of hydrated
Cl species induces the formation of oxidized Cl species.