Influence of mixed methods on the surface area and gas products of activated carbon

A Correction to this article was published on 19 March 2020

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Upgraded activated carbons (ACs) are typically synthesized by mixed methods, such as solid–solid mixing and wet impregnation of low-grade ACs with KOH. This study compares the properties of upgraded ACs prepared by different methods using elemental analysis, X-ray photoelectron spectroscopy, N2 adsorption isotherms, and X-ray diffraction. In ACs produced by the solid–solid mixing, the ratio of potassium activator is proportional to the surface area and amount of gas produced. However, in wet impregnated ACs, the potassium ratio exhibits a zero or negative correlation. It is demonstrated that potassium ions in solution are not transferred to K2O and do not contribute to the surface area and pore size, generating less amount and different composition of gases. As such, impregnated ACs exhibit similar surface areas and large pores, regardless of the potassium ratio. The physical properties, such as specific surface areas and pore size distribution, of ACs using wet impregnation were similar to the ACs generated by the water physical activation. It indicated that the KOH does not efficiently act as a chemical activator in the wet impregnation method. Therefore, a certain amount and suitable mixing method of chemical activator play an important role in the property upgrade of ACs.

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  • 19 March 2020

    Unfortunately, the funding note has been omitted during the e-proofing.


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This study was supported by the Energy Development Technology Program of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) granted financial resource from the Ministry of Trade, Industry & Energy, republic of Korea (Project No. 20162010104680), and also the National Research Foundation of Korea (NRF) and the Center for Women In Science, Engineering and Technology (WISET) Grant funded by the Ministry of Science and ICT under the Program for Returners into R&D.

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Correspondence to Jung Eun Park.

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Hwang, S.Y., Lee, G.B., Kim, H. et al. Influence of mixed methods on the surface area and gas products of activated carbon. Carbon Lett. 30, 603–611 (2020).

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  • Activated carbon
  • Potassium hydroxide
  • Chemical activation
  • Carbon monoxide
  • Surface area