2.3. Synthesis of LDH

The MgAl–Cl–LDH (LDH) were prepared using a co-precipitation method [13]. A solution of MgCl₂·6H₂O (0.67 g, 7 mmol) and AlCl₃ (0.72 g, 3 mmol) in water (10 mL) was slowly added dropwise to a vigorously stirred solution (40 mL) containing NaOH (0.72 g, 18 mmol) at room temperature within 30 min. The LDH slurry was centrifuged at 500 g for 10 min and the pellet washed three times with deionized water (40 mL) until an almost neutral pH was reached. After adding deionized water (40 mL), the suspension was transferred into a stainless-steel autoclave with a Teflon lining and heated at 100 °C for 16 h. The final concentration of LDH suspension, obtained after lyophilization, was 10 mg mL⁻¹.