Preparation of copper-loaded porous carbons through hydrothermal carbonization and ZnCl2 activation and their application to selective CO adsorption: Experimental and DFT calculation studies

Heesun Yun; Yu Jin Kim; Seung Bin Kim; Hyung Jin Yoon; Sang Kyu Kwak; Ki Bong Lee

doi:10.1016/j.jhazmat.2021.127816

Preparation of copper-loaded porous carbons through hydrothermal carbonization and ZnCl₂ activation and their application to selective CO adsorption: Experimental and DFT calculation studies

J Hazard Mater. 2022 Mar 15:426:127816. doi: 10.1016/j.jhazmat.2021.127816. Epub 2021 Nov 20.

Authors

Heesun Yun¹, Yu Jin Kim², Seung Bin Kim¹, Hyung Jin Yoon¹, Sang Kyu Kwak³, Ki Bong Lee⁴

Affiliations

¹ Department of Chemical and Biological Engineering, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea.
² Department of Energy Engineering, School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea.
³ Department of Energy Engineering, School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea. Electronic address: skkwak@unist.ac.kr.
⁴ Department of Chemical and Biological Engineering, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea. Electronic address: kibonglee@korea.ac.kr.

PMID: 34865899
DOI: 10.1016/j.jhazmat.2021.127816

Abstract

CO is used as a raw material to produce valuable chemicals. Adsorption using solid materials can be employed to separate and recover CO from gas mixtures. In this study, cellulose-based, porous carbons were prepared via hydrothermal carbonization and ZnCl₂ activation. The prepared porous carbons were used for CO separation after CuCl loading by a facile solid-state dispersion method to induce π-complexation and eventually enhance the affinity toward CO. The sample with the highest CO uptake of 3.62 mmol g^-1 at 298 K and 101 kPa had a carbon:CuCl loading ratio of 1:1. This is the highest reported CO adsorption on porous carbons using CuCl as a π-complexation-inducing material. In addition, several factors, including the selectivity of CO against CO₂ and the cyclic stability using vacuum regeneration, demonstrated the potential for industrial applications. Density functional theory (DFT) calculations theoretically elucidated that the presence of small and well-dispersed CuCl clusters induce excellent CO-selective adsorption performance, which is in accordance with the experimental results.

Keywords: CO; Density functional theory; Solid-state dispersion; Vacuum regeneration; π-complexation.