The Effect of Surface Composition on the Selective Capture of Atmospheric CO2 by ZIF Nanoparticles: The Case of ZIF-8

Autor(es)

Vendite, Alexsander C. ; Soares, Thereza A. . ; Coutinho, Kaline

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF CHEMICAL INFORMATION AND MODELING; v. 62, n. 24, p. 14-pg., 2022-09-23.

Resumo

We performed theoretical studies of CO2 capture in atmospheric conditions by the zeolitic imidazolate framework-8 (ZIF-8) via classical Monte Carlo (MC) simulations with Metropolis sampling and classical molecular dynamics (MD) simulations in the NVT and NPT ensembles and different thermodynamic conditions. The ZIF-8 framework was described by varying unit cell dimensions in the presence of pure gases of CO2, N-2, O-2, Ar, and H2O steam as well as binary mixtures of CO2:N(2 )and CO2:H2O in s 1:1 concentration. Different chemical compositions of the framework surface was considered to provide an accurate treatment of charge and charge distribution in the nanoparticle. Hence, surface groups were represented as unsaturated zinc atom (Zn+2), 2-methylimidazole (mImH), and deprotonated 2-methylimidazole (mIm-). Force field reparameterization of the surface sites was required to reproduce the interactions of the gas molecules with the ZIF-8 surface consistent with quantum mechanics (QM) calculations and Born-Oppenheimer molecular dynamics (BOMD). It was observed that ZIF-8 selectively captures CO2 due to the negligible concentrations of N-2, O-2, Ar, and H2O. These molecules spontaneously migrate to the inner pores of the framework. At the surface, there is a competitive interaction between H2O, CO2, and N-2, for the positively charged ZIF-8 nanoparticle with a large binding energy advantage for water molecules (on average -62, -15, and -8 kcal/mol respectively). For the neutral ZIF-8 nanoparticle, the water molecules dominate the interactions due to the occurrence of hydrogen bond with the imidazolate groups at the surface. Simulations of binary mixtures of CO2/water steam and CO2/N-2 were performed to investigate binding competition between these molecules for the framework positively charged and neutral surfaces. It was found that water molecules drastically block the interaction between CO2 molecules and the framework surface, decreasing CO2 capture in the central pore, and CO2 molecules fully block the interaction between N(2 )molecules and the framework. These findings show that CO2 capture by ZIF-8 is possible in atmospheric environments only upon dehydration of the atmospheric gas. It further shows that ZIF-8 capture of CO2 from the atmospheric environment is dependent on thermodynamic conditions and can be increased by decreasing temperature and/or increasing pressure. (AU)

• Processo FAPESP: 21/09016-3 - Caracterização estrutural e eletrônica de moléculas biogênicas emitidas pela flora amazônica
• Beneficiário: Kaline Rabelo Coutinho
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 19/08465-9 - Estudos teóricos de captura de CO2 em gás atmosférico por nanopartículas porosas
• Beneficiário: Alexsander Carvalho Vendite
• Modalidade de apoio: Bolsas no Brasil - Mestrado
• Processo FAPESP: 21/04283-3 - Uma abordagem de múltipla resolução para o polimorfismo de agregados lipopolissacarídicos induzido por metais
• Beneficiário: Thereza Amélia Soares da Silva
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 17/11631-2 - CINE: desenvolvimento computacional de materiais utilizando simulações atomísticas, meso-escala, multi-física e inteligência artificial para aplicações energéticas
• Beneficiário: Juarez Lopes Ferreira da Silva
• Modalidade de apoio: Auxílio à Pesquisa - Programa Centros de Pesquisa em Engenharia