Sonochemical surface functionalization of exfoliated LDH: effect on textural properties, CO2 adsorption, cyclic regeneration capacities and subsequent gas uptake for simultaneous methanol synthesis

Collins I. Ezeh, Xiani Huang, Xiaogang Yang*, Cheng-Gong Sun, Jiawei Wang

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

To improve CO2 adsorption, amine modified Layered double hydroxide (LDH) were prepared via a two stage process, SDS/APTS intercalation was supported by ultrasonic irradiation and then followed by MEA extraction. The prepared samples were characterised using Scanning electron microscope-Energy dispersive X-ray spectroscopy (SEM-EDX), X-ray Photoelectron Spectroscopy (XPS), X-ray diffraction (XRD), Temperature Programmed Desorption (TPD), Brunauer-Emmett-Teller (BET), and Thermogravimetric analysis (TGA), respectively. The characterisation results were compared with those obtained using the conventional preparation method with consideration to the effect of sonochemical functionalization on textural properties, adsorption capacity, regeneration and lifetime of the LDH adsorbent. It is found that LDHs prepared by sonochemical modification had improved pore structure and CO2 adsorption capacity, depending on sonic intensity. This is attributed to the enhanced deprotonation of activated amino functional groups via the sonochemical process. Subsequently, this improved the amine loading and effective amine efficiency by 60% of the conventional. In addition, the sonochemical process improved the thermal stability of the adsorbent and also, reduced the irreversible CO2 uptake, CUirrev, from 0.18 mmol/g to 0.03 mmol/g. Subsequently, improving the lifetime and ease of regenerating the adsorbent respectively. This is authenticated by subjecting the prepared adsorbents to series of thermal swing adsorption (TSA) cycles until its adsorption capacity goes below 60% of the original CO2 uptake. While the conventional adsorbent underwent a 10 TSA cycles before breaking down, the sonochemically functionalized LDH went further than 30 TSA cycles.

Original languageEnglish
Pages (from-to)330-343
Number of pages14
JournalUltrasonics Sonochemistry
Volume39
Early online date3 May 2017
DOIs
Publication statusPublished - Nov 2017

Bibliographical note

© 2017, Elsevier. Licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/

Funding: Zhejiang Provincial Natural Science Foundation (LY15B060001); Ningbo Key Research Project (1012B10042); Ningbo Education Bureau; University of Nottingham; and EPSRC (Grant no. EP/G037345/1).

Keywords

  • adsorption
  • CO capture
  • layered double hydroxide
  • regeneration
  • ultrasound

Fingerprint

Dive into the research topics of 'Sonochemical surface functionalization of exfoliated LDH: effect on textural properties, CO<sub>2</sub> adsorption, cyclic regeneration capacities and subsequent gas uptake for simultaneous methanol synthesis'. Together they form a unique fingerprint.

Cite this