*2.3. Mg-Al LDH*

Commercial grade MgO (86%, Chamotte Holdings, JHB, GP, ZA) was initially calcined at 800 ◦C for 1 h to eliminate carbonate and hydroxide contaminants. This was then milled with Al(OH)3 (Hindalco, Belgaum, India) making use of a 2:1 (28.63 g MgO, 23.83 g Al(OH)3) (S1) and 3:1 (33.79 g MgO, 18.75 g Al(OH)3) (S2), MII:MIII metal ratio [15,26]. The selected MgO contained SiO2 as an impurity and was prevalent in all relevant samples collected.
