Adsorption of hydrogen and carbon dioxide in zeolitic imidazolate framework structure with SOD topology: experimental an

  • PDF / 2,688,080 Bytes
  • 12 Pages / 595.276 x 790.866 pts Page_size
  • 49 Downloads / 238 Views

DOWNLOAD

REPORT


Adsorption of hydrogen and carbon dioxide in zeolitic imidazolate framework structure with SOD topology: experimental and modelling studies Rimita Bose1 · Jayashree Ethiraj2 · Palla Sridhar1 · Jithin J. Varghese1 · Niket S. Kaisare1 · Parasuraman Selvam2,3,4 Received: 28 October 2019 / Revised: 4 March 2020 / Accepted: 13 March 2020 © Springer Science+Business Media, LLC, part of Springer Nature 2020

Abstract The aim of this work is to develop insights into adsorption of hydrogen and carbon dioxide in a zeolitic imidazolate framework, ZIF-8, using high-pressure adsorption studies, adsorption isotherm model fitting, and DFT investigation of preferential adsorption sites and binding energies. The robustness of ZIF series metal–organic frameworks has drawn interest towards its utility in large scale applications in gas storage and separation. We use room temperature synthesis of ZIF-8 using DMF as a solvent, and benchmarked it against typical solvothermal synthesis. The resulting material is characterized using XRD, SEM, TG–DSC and N ­ 2 adsorption isotherm. High-pressure volumetric adsorption of the activated materials is conducted to analyze the hydrogen and carbon dioxide storage capacities up to 50 and 40 bar, respectively. ZIF-8 shows maximum H ­ 2 storage capacity of 3.13 wt% at 50 bar and 77 K, and ­CO2 storage capacity of 46 wt% at 40 bar and 300 K. The parameters of Unilan adsorption isotherm are estimated from the equilibrium adsorption data and isosteric heats of adsorption for H ­ 2 and ­CO2 on ZIF-8 are computed. DFT calculations are used to obtain preferential adsorption sites of ­H2 and ­CO2. Adsorption enthalpy values were calculated from DFT as − 7.08 and − 25.98 kJ/mol, respectively for ­H2 and ­CO2 at the most preferred sites. We found a close agreement between isosteric heat of adsorption of hydrogen (− 4.68 kJ/mol) and the enthalpy of hydrogen adsorption from DFT (− 6.04 kJ/mol) at 77 K. Keywords  High-pressure adsorption · Hydrogen · Carbon dioxide · Metal–organic framework · ZIF-8 · Unilan model · Density functional theory

1 Introduction

Electronic supplementary material  The online version of this article (https​://doi.org/10.1007/s1045​0-020-00219​-2) contains supplementary material, which is available to authorized users. * Parasuraman Selvam [email protected] 1



National Centre for Catalysis Research and Department of Chemical Engineering, Indian Institute of TechnologyMadras, Chennai 600036, India

2



National Centre for Catalysis Research and Department of Chemistry, Indian Institute of Technology-Madras, Chennai 600036, India

3

School of Chemical Engineering and Analytical Science, The University of Manchester, Manchester M13 9PL, UK

4

Department of Chemical and Process Engineering, University of Surrey, Guildford, Surrey GU2 7XH, UK



Technological advancement in this growing civilization demands higher and efficient production of energy from renewable and environment-friendly sources and also protection of the environment from the adverse effects of existing technology. W