Screening of gallate-based metal-organic frameworks for single-component CO₂ and CH₄ gas

Abstract

Adsorption using porous adsorbents is widely applied in carbon dioxide (CO2) capture due to its potential energy saving with low operating cost. Metal-organic frameworks (MOFs) are preferable over conventional adsorbents as MOFs have tunable structure properties. Organic linkers from phytochemical-based give a new idea in forming MOFs. Gallic acid is classified under phytochemicals can act as an alternative organic linker in a new family of hybrid framework materials due to low cost, low toxicity, easy availability and naturally abundant. Due to unique property of MOFs that can be tailored, screening using systematic tool is very important. Molecular modeling is proven to play a crucial role in providing an estimation on adsorption capacity, selectivity and adsorbent selection. Grand Canonical Monte Carlo (GCMC) method via Sorption module in Material Studio was performed to compute loading curves of CO2 and methane (CH4) in MOFs. Based on the simulation results, it shows that gallate-based MOFs can be a new promising adsorbent in CO2 capture as the predicted CO2 loading is significantly higher than CH4. The highest predicted CO2 adsorption capacity is achieved by Mg-gallate and the lowest is by Ag-gallate with 7.79 mmol/g and 6.35 mmol/g respectively. The applicability of gallic acid to act as an alternative linker is relevant for practical applications.

Ideal Adsorbed Solution Theory (IAST) of Carbon Dioxide and Methane Adsorption Using Magnesium Gallate Metal-Organic Framework (Mg-gallate)

“…Carbon dioxide (CO 2 ) and methane (CH 4 ) mixture separation is a key challenge for the energy sector and crucial to provide high purity natural gas that meets gas sales specifications. In our previous reported work, the feasibility of gallate-based MOFs for CO 2 and CH 4 single-component adsorption was predicted using Grand Canonical Monte Carlo (GCMC) simulation [ 9 ]. Among the studied gallate-based MOFs, Mg-gallate showed the highest predicted CO 2 adsorption capacity and CO 2 /CH 4 selectivity [ 9 ].…”

“…In our previous reported work, the feasibility of gallate-based MOFs for CO 2 and CH 4 single-component adsorption was predicted using Grand Canonical Monte Carlo (GCMC) simulation [ 9 ]. Among the studied gallate-based MOFs, Mg-gallate showed the highest predicted CO 2 adsorption capacity and CO 2 /CH 4 selectivity [ 9 ]. The magnesium atom exhibits a significant contribution in the conduction band of states, leading to possible Lewis acidic activity in crystalline materials [ 10 ].…”

Unary Adsorption Isotherm of Carbon Dioxide and Methane of Nickel Gallate Metal-organic Framework

“…According to our previous reported work, Grand Canonical Monte Carlo (GCMC) simulation suggested that the nickel gallate metal-organic framework (Ni-gallate) has the potential to serve as a cost-effective adsorbent for the separation of CO 2 and CH 4 based on the predicted unary adsorption isotherms [9]. In addition, Ni-gallate demonstrated remarkable performance in CO 2 and CH 4 adsorption, as indicated by experimental unary adsorption isotherms [10].…”

Screening and Experimental Validation for Selection of Open Metal Sites Metal-Organic Framework (M-CPO-27, M = Co, Mg, Ni and Zn) to Capture CO2

“…A new invention of adsorbents has been found by researchers, which provides a higher adsorption capacity of CO 2 with a higher surface area of solid sorbents compared with conventional adsorbents [7,11]. Currently, multiple promising adsorbents, such as Zeolite 5A, MIL-101 (Cr), Mg-Gallate, and Metal-Organic Frameworks, offer higher CO 2 adsorption capacities [12,13]. The addition of certain binding sites at the pore surface, such as amines acting as Lewis bases and coordinatively unsaturated metal cations actinig as Lewis acids, can improve high absorption under ambient conditions in porous materials [7].…”

“…Magnesium metal is reported to be the best metal center due to its lighter molecular weight, which is 23.405 g/mol compared with zinc (65.38 g/mol) and nickel (58.69 g/mol) [23]. Ismail et al [13] also worked on MOFs using gallic acid as an alternative linker for enhancing the CO 2 capacity. The authors found that Mg-gallate has a maximum predicted adsorption capacity of 7.79 mmol/g.…”