Potassium and Zeolitic Structure Modified Ultra-microporous Adsorbent Materials from a Renewable Feedstock with Favorable Surface Chemistry for CO2 Capture

Liu, Xin; Sun, Yuan; Liu, Jingjing; Sun, Chenggong; Liu, Hao; Xue, Qian; Smith, Emily; Snape, Colin

Abstract

© 2017 American Chemical Society. Novel hierarchically structured microporous biocarbons with exceptionally high capacities for CO2 capture have been synthesized from the abundant agricultural waste of rice husk (RH), using a facile methodology that effectively integrated carbonization, activation, and potassium intercalation into a one-step process. Textural characterization demonstrates that the synthesized biocarbons exhibit exceedingly high ultra-microporosity accounting for up to 95% of total porosity mainly as a result of the naturally occurring silicon compounds within the RH molecular framework structures. With a modest surface area of up to 1035 m2/g and a total pore volume of 0.43 cm3/g, the best performing RH carbon has shown exceptionally high and fully reversible CO2 uptake capacity of 2.0 mmol/g at 25 °C and a CO2 partial pressure of 0.15 bar, which represents one of the highest uptakes ever reported for both carbon and MOF materials usually prepared from using cost-prohibitive precursor materials with cumbersome methodologies. It has been found that up to 50% of the total CO2 uptake is attributable to the unique surface chemistry of the RH carbons, which appears to be dominated by the enhanced formation of extra-framework potassium cations owing to the exceedingly high levels of ultra-microporosity and the presence of zeolitic structures incorporated within the carbon matrices. Characterizations by EDX element mapping, XPS, and heat of adsorption measurements confirm the existence of a range of zeolitic structures, which essentially transforms the RH carbons into a kind of zeolite-carbon nanocomposite material with strong surface affinity for CO2.

Citation

Liu, X., Sun, Y., Liu, J., Sun, C., Liu, H., Xue, Q., Smith, E., & Snape, C. (2017). Potassium and Zeolitic Structure Modified Ultra-microporous Adsorbent Materials from a Renewable Feedstock with Favorable Surface Chemistry for CO2 Capture. ACS Applied Materials and Interfaces, 9(32), 26826-26839. https://doi.org/10.1021/acsami.7b06665

• Journal Article Type: Article
• Acceptance Date: Jul 11, 2017
• Publication Date: Aug 16, 2017
• Deposit Date: Jul 12, 2017
• Publicly Available Date: Aug 16, 2017
• Journal: ACS Applied Materials and Interfaces
• Electronic ISSN: 1944-8244
• Publisher: American Chemical Society
• Peer Reviewed: Peer Reviewed
• Volume: 9
• Issue: 32
• Pages: 26826-26839
• DOI: https://doi.org/10.1021/acsami.7b06665
• Keywords: CO2 capture, carbon materials, rice husk, surface chemistry, ultra-microporosity
• Public URL: https://nottingham-repository.worktribe.com/output/872112
• Publisher URL: http://pubs.acs.org/doi/abs/10.1021/acsami.7b06665
• Additional Information: This document is the Accepted Manuscript version of a Published Work that appeared in final form in; ACS Applied Materials & Interfaces, copyright © American Chemical Society after peer review and technical editing by the publisher.; To access the final edited and published work see http://dx.doi.org/10.1021/acsami.7b06665
• Contract Date: Jul 12, 2017