Controlled Covalent Functionalization of ZIF-90 for Selective CO2 Capture & Separation

Muhammad Usman; Mohd Yusuf Khan; Tanzila Anjum; Asim Laeeq Khan; Bosirul Hoque; Aasif Helal; Abbas Saeed Hakeem; Bassem A Al-Maythalony

doi:10.3390/membranes12111055

Controlled Covalent Functionalization of ZIF-90 for Selective CO₂ Capture & Separation

Membranes (Basel). 2022 Oct 27;12(11):1055. doi: 10.3390/membranes12111055.

Authors

Muhammad Usman¹, Mohd Yusuf Khan¹, Tanzila Anjum², Asim Laeeq Khan², Bosirul Hoque¹, Aasif Helal¹, Abbas Saeed Hakeem¹, Bassem A Al-Maythalony^{3

4}

Affiliations

¹ Interdisciplinary Research Center for Hydrogen and Energy Storage (IRC-HES), King Fahd University of Petroleum & Minerals (KFUPM), Dhahran 31261, Saudi Arabia.
² Department of Chemical Engineering, Lahore Campus, COMSATS University, Islamabad 54000, Pakistan.
³ King Abdulaziz City for Science and Technology-Technology Innovation Center on Carbon Capture and Sequestration (KACST-TIC on CCS), King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia.
⁴ Materials Discovery Research Unit, Advanced Research Center, Royal Scientific Society, Amman 11941, Jordan.

Abstract

Mixed Matrix Membranes (MMM) with enhanced selectivity and permeability are preferred for gas separations. The porous metal-organic frameworks (MOFs) materials incorporated in them play a crucial part in improving the performance of MMM. In this study, Zeolitic imidazolate frameworks (ZIF-90) are selected to fabricate Polyetherimide (PEI) MMMs owing to their lucrative structural and chemical properties. This work reports new controlled post-synthetic modifications of ZIF-90 (50-PSM-ZIF-90) with ethanolamine to control the diffusion and uptake of CO2. Physical and chemical properties of ZIF-90, such as stability and presence of aldehyde functionality in the imidazolate linker, allow for easy modulation of the ZIF-90 pores and window size to tune the gas transport properties across ZIF-90-based membranes. Effects of these materials were investigated on the performance of MMMs and compared with pure PEI membranes. Performance of the MMMs was evaluated in terms of permeability of different gases and selective separation of CO2 and H2 gas. Results presented that the permeability of all membranes was in the following order, i.e., P(H2) > P(CO2) > P(O2) > P(CH4) > P(C2H6) > P(C3H8) > P(N2), demonstrating that kinetic gas diffusion is the predominant gas transport mode in these membranes. Among all the membranes, permeability of pure PEI membrane was highest for all gases due to the uniform porous morphology. The pure PEI membrane showed highest permeability of H2, which is 486.5 Barrer, followed by 49 Barrer for O2, 29 Barrer for N2, 142 Barrer for CO2, 41 Barrer for CH4, 40 Barrer for C2H6 and 39.6 Barrer for C3H8. Results also confirm the superiority of controlled PSM-ZIF-90-PEI membrane over the pure PEI and ZIF-90-PEI membranes in CO2 and H2 separation performance. The 50-PSM-ZIF-90 PEI membrane exhibited a 20% increase in CO2 separation from methane and a 26% increase over nitrogen compared to the ZIF-90-PEI membrane. The 50-PSM-ZIF-90 PEI membrane showed 15% more H2/O2 separation and 9% more H2/CH4 separation than ZIF-90 PEI membrane. Overall, this study represents the role of controlled PSM in enhancing the property of new materials like ZIF and its application in MMMs fabrication to develop a promising approach for the CO2 capture and separation.

Keywords: CO2 capture; CO2 separation; ZIF-90; ethanolamine; functionalization; membranes.

Grants and funding

This research was funded by the Deanship of Research Oversight and Coordination (DROC) at King Fahd University of Petroleum and Minerals (KFUPM).