MXene-supported stable adsorbents for superior CO2 capture

Abstract

Polyamine-based solid adsorbents are promising candidates for CO₂ capture, but long-term stability under practical regeneration conditions (100% CO₂ at 120 °C) remains the biggest hurdle. In this paper, we prepared MXene-supported adsorbents with excellent long-term stability by combining two strategies. First, 1,2-butylene oxide (BO) with an epoxy group was grafted onto polyethyleneimine (PEI) to suppress the formation of urea. Second, Ti₃C₂(OH)_x MXene was used as the support of polyamines to improve the wear resistance and thermal conductivity. The prepared MXene-supported adsorbents exhibit a large working capacity (2.6 mmol g⁻¹) and a very stable cycling stability because of the synergetic effect. The adsorbents also exhibit a very low regeneration heat of 1.90 MJ per kg (CO₂) and a high mechanical stability against attrition (0.26% after 5 h time-on-stream). Thus, these MXene-supported adsorbents make the CO₂ capture process promising.