Synthesis and Characterization of MSU-2 for CO2 Adsorption

Abstract

The advancement of adsorption technology is highly dependent on the characteristics of the adsorbents used. However, the commonly used one-dimensional (1D) MCM-41 and two-dimensional (2D) SBA-15 were found to induce gas diffusion difficulty. With this, MSU-2 was introduced as it shows high potentiality to be employed as CO2 adsorbent due to its excellent properties such as the highly interconnected three-dimensional (3D) wormhole-like framework structure as well as large specific surface area, total pore volume and pore size. The focus of the current study focuses on the synthesis of MSU-2 and the investigation on the CO2 adsorption capacity of the synthesized MSU-2 at various temperatures and pressures. The preparation of the MSU-2 was achieved by fluoride-assisted two-step process of solution precipitation method involving the addition of tetraethylorthosilicate (TEOS) to the acidified aqueous solution of nonionic surfactant, Triton X-100. The resultant MSU-2 was characterized by SEM, TEM, SAP analyser, XRD, FTIR spectrometer and TGA. The analyzed results showed that MSU-2 with desired features was successfully synthesized. The CO2 gas adsorption studies of the MSU-2 was demonstrated at different temperatures (25 °C and 85 °C) and different pressures (1 bar and 5 bar) to study the effect of temperatures and pressures on the CO2 adsorption capacity of the MSU-2. The highest CO2 adsorption capacity of the MSU-2 was found to be 0.98 mmol-CO2/g-adsorbent when the operating conditions were set at 25 °C and 5 bar. This adsorption experiment also deduced that low adsorption temperature and high operating pressure promote adsorption process which give higher CO2 adsorption capacity.