Articles written in Bulletin of Materials Science
Volume 38 Issue 7 December 2015 pp 1783-1790
Metal oxides in general have surface acidic sites, but for exceptional circumstances, are not expected to mineralize CO2. Given their intrinsic basicity and an expandable interlayer gallery, the hydrotalcite-like layered double hydroxides (LDHs) are expected to be superior candidate materials for CO2 mineralization. However, the incorporation of Al3+ adversely impacts the ability of the metal hydroxide layer to interact with CO2 in the gas phase in comparison with the unitary Mg(OH)2. Thermogravimetric analysis shows that the decomposition reaction of the [Mg–Al–CO3] LDH is only marginally delayed in flowing CO2 in comparison with flowing N2, showing only an apparent marginal CO2 uptake. Al3+ ion severely attenuates the surface basicity of the LDHs, as the unitary Al(OH)3 is acidic in comparison with Mg(OH)2 and shows little or no interaction with CO2 in the gas phase.
Volume 41 Issue 1 February 2018 Article ID 0026
NO$^−_2$ and SCN$^−$ are two common small inorganic anions. The former is a common industrial pollutant. Thelatter is linear and is a good mimic for the toxic CN$^−$ ion. The structures of these two anions are refined within the gallery ofthe [Zn–Al]-layered double hydroxide (LDH). Both LDHs crystallize as mixed anion phases. The nitrite is found to co-existwith the nitrate ion. The nitrite ion is intercalated with its molecular plane inclined to the metal hydroxide layer. In the caseof the SCN$^−$ intercalated LDH, no other anion was detected by ion chromatography, suggesting that the SCN$^−$ deficiencyis compensated by intercalated hydroxyl ions. In this case, the SCN$^−$ ion is found to be intercalated with its molecular axisinclined to the metal hydroxide layer.
Volume 42 | Issue 3