MgAl ‐layered double hydroxide/activated carbon catalyst enabling fast CO ₂ absorption in t

Abstract

The practical utilization of tertiary amine solvents in CO ₂ capture is restricted because of their slow kinetics of CO ₂ absorption. Herein, this study designed an innovative solid base catalyst, a layered double hydroxide/activated carbon (LDH/AC) composite catalyst, that greatly accelerates CO ₂ absorption. LDH/AC utilizes high surface area, strong basic sites, and abundant oxygen vacancies to boost CO ₂ absorption in N‐methyldiethanolamine solution (MDEA) via a base‐catalyzed mechanism. Only 0.1 wt% dosage of LDH/AC _1:1 increases the CO ₂ absorption rate by 256% as compared to the non‐catalyzed MDEA system, and keeps excellent stability after 10 cycles. Online FT‐IR provided additional evidence of the LDH/AC _1:1 catalyst's synergistic enhancing impact. Furthermore, theoretical calculations reveal a 47% reduction in the reaction energy barrier of the rate‐limiting step, providing molecular‐level proof for the catalytic absorption enhancement. This study offers a promising route for developing high‐efficiency and sustainable CO ₂ capture technologies using solid base catalysts.