CO₂ Adsorption on Modified Mg–Al-Layered Double Hydroxides

Abstract

Because of increases in the burning of fossil fuels, there is an increased emission of pollutant gases (e.g. CO 2 ) into the atmosphere. An alternative to minimize these emissions is to capture these gases using porous materials, such as layered double hydroxides (LDHs). In this study, LDHs were synthesized by co-precipitation of ion salts of Mg 2+ and Al 3+. After the synthesis, the materials were treated with a template to expand the layers. The samples were then characterized by X-ray diffraction, thermogravimetric analysis/derivative thermogravimetry, adsorption/desorption of nitrogen, scanning electron microscopy/energy-dispersive X-ray spectroscopy and transmission electron microscopy. A CO 2 adsorption study was then performed to determine the adsorption capacity of the material in accordance with the contact time between the gas and the adsorbent. The adsorption capacities of LDHs and LDHs-P123 for CO 2 were 0.72 and 1.36 mmol/g, respectively, showing satisfactory results post-treatment.

New Insights into CO2 Adsorption on Layered Double Hydroxide (LDH)-Based Nanomaterials

“…7 , CO 2 adsorption amounts on APS/LDHs increased dramatically within the first 30 min, followed by a slow saturation stage. A CO 2 adsorption capacity as high as 2.09 mmol/g during this saturation stage was obtained, much higher than that of LDHs (typically less than 1.0 mmol/g [ 29 – 31 ]). Therefore, the incorporated amino groups contributed to CO 2 capturing significantly.…”

Layered double hydroxides and LDH-derived materials in chosen environmental applications: a review

“…For example, steam reforming of hydrocarbons (Marquevich et al 2001;Ashok et al 2008;Li et al 2011), that is the most suitable process for hydrogen production, releases high amounts of carbon dioxide. Considering the large field of materials tested for CO 2 capture and storage, zeolites, hydrotalcite and LDH-derived mixed oxides are widely studied thanks to their high surface area, pore structure, and charge density (Mao and Tamaura 1993;Tsuji et al 1993;Yong et al 2002;Wang et al 2010;Dantas et al 2015;Yang et al 2019). Several reviews on CO 2 adsorption explain that an appropriate adsorbent should satisfy several criteria such as 1low-cost materials, (2) fast kinetics, (3) high adsorption capacity and selectivity, and 4thermal and chemical stability towards several cycles (Yong et al 2002;León et al 2010;Wang et al 2017;Yang et al 2019).…”

“…Moreover, these materials can be regenerated several times, without losing their adsorption capacity and selectivity towards CO 2 , are hydrothermally stable, and lead to fast sorption kinetics. A huge amount of studies has been performed on these materials in order to find the most efficient preparation route for CO 2 capture, such as impregnation of commercial hydrotalcites (Bhatta et al 2015), synthesis of tunable Mg/Al hydrotalcites (Tsuji et al 1993;Moreira et al 2006;Dantas et al 2015), and mixed oxides derived from hydrotalcites (León et al 2010;Gao et al 2013;Radha and Navrotsky 2014;Colonna et al 2018). Table 2 summarizes the synthesis conditions, the specific surface area, and the CO 2 adsorption capacity of the LDHs and related mixed oxides.…”

“…This impregnation leads to high adsorption capacities, as demonstrated by Bhatta et al (2015): values up to 1.10 mmol.g -1 at 300°C for the initial sorption cycle, and of 0.42 mmol.g -1 for the following 9 cycles of adsorption/desorption were measured. Polymers addition can modify the textural properties of layered materials and contribute to the enhancement of the CO 2 sorption capacity, as showed by Dantas et al (2015) by the addition of a co-polymer that increased the CO 2 uptake from 0.72 to 1.36 mmol.g -1 . Tang et al (2018) increased the basal spacing of LDHs by exchanging anions with dodecylsulfonate ions in order to chemically graft (3-aminopropyl)triethoxysilane (APS) and enhance the CO 2 sorption capacity (up to 2.09 mmol.g -1 at 50°C).…”

Effectiveness of amino-functionalized sorbents for co2 capture in the presence of Hg

“…The success of novel adsorption technologies for CO 2 capture is dependent on the development of new materials with a high adsorption capacity, a high CO 2 selectivity, durability and relatively fast sorption and desorption kinetics [2]. Several solid porous adsorbents [3,4], such as zeolites [5], activated carbon [6], metal oxides [7][8][9], and metal-organic frameworks [10] have been proposed for physisorption. The use of industrial [11], agricultural [12] and domestic wastes [13], together with silicates [14], cellulose [15] or clays [16][17][18] have been studied.…”