Theoretical study of CO2 capture in porous materials: ZIF-78 and similars

• Grant number: 20/01187-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2020
• End date: January 31, 2022
• Field of knowledge: Physical Sciences and Mathematics - Physics - Atomic and Molecular Physics
• Principal Investigator: Kaline Rabelo Coutinho
• Grantee: Emanuel Fernandes Dias Mancio
• Host Institution: Instituto de Física (IF). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Company: Universidade de São Paulo (USP). Instituto de Química de São Carlos (IQSC)
• Associated research grant: 17/11631-2 - CINE: computational materials design based on atomistic simulations, meso-scale, multi-physics, and artificial intelligence for energy applications, AP.PCPE

Abstract

Metal-Organic Frameworks (MOFs) are a class of crystalline materials with structured nanopores that have been the focus of intense research over the past decade. Although the potential of MOFs for CO2 capture is recognized, a systematic characterization of the interactions between MOFs and the most abundant molecules in atmospheric gas, and how these interactions can be chemically modulated to allow greater selectivity remains absent in the scientific literature. Among the MOFs, ZIF-78, which has a topology known as gelinelin (GME), is a major candidate for CO2 capture. It has high selectivity of CO2 over CH4 and N2, abundant gases in the atmosphere. Comparing it with its similar (other ZIF-GME), although it has a smaller central pore, it is identified greater selectivity and CO2 capture capacity. Such features make it a counterexample to the common understanding that there is a direct ratio between central pore size and gas absorption capacity. In addition, the presence of a smaller pore and an increase in experimentally observed CO2 absorption energy may indicate that the surface effect is important in the capture process. Therefore, a theoretical study of ZIF-78 comparing surface and pore interactions may provide a better understanding of the mechanisms involved in CO2 capture processes. In this project, we will perform atom-level computational simulations of ZIF-78 nanoparticles with gases of abundant molecules in atmospheric gas and CO2 to better understand surface and pore interactions.