Niobium-Modified HZSM-5 Zeolite Catalyzes Low-Energy Regeneration of CO2-Captured Amine Solution

作者：Yingyang Song, Junyu Lang, Qingrui Zeng, Jinping Cheng, Mingce Long · 发表于：ACS Sustainable Chemistry & Engineering · 年份：2024 · DOI：10.1021/acssuschemeng.4c00200 · 被引用次数：32 · 研究领域：Carbon Dioxide Capture Technologies、Membrane Separation and Gas Transport、Carbon dioxide utilization in catalysis

Monoethanolamine (MEA)-based carbon dioxide absorption is one of the effective carbon capture, utilization, and storage (CCUS) technologies but is significantly restricted by the high energy consumption in the regeneration of rich amine solution. Solid acid catalysts have the potential to reduce energy consumption, while the exploration of highly active catalysts with abundant Bro̷nsted and Lewis acid sites remains needing. We developed an efficient solid acid catalyst, niobium-modified HZSM-5 (Nb/HZ), to facilitate CO 2 desorption from the CO 2 -captured MEA solutions. The Nb/HZ catalysts with various niobium loadings were synthesized by using an impregnation method. HZSM-5 retained its pore structure and large surface area after niobium incorporation. The catalyst with 4% Nb (4.0-Nb/HZ) has the highest activity and stability, with 61% increase in the desorption rate, 50% increase in the desorbed CO 2 amount, and 37% reduction of relative heat duty. According to theoretic calculations and experimental analyses, the Nb/HZ catalyst provides abundant Bro̷nsted and Lewis acid sites to facilitate carbamate adsorption, proton transfer, and carbamate breakdown, thus reducing the activation energy for CO 2 desorption. This work provides a valuable solid acid catalyst for amine-based CO 2 capture and also brings insights for the development of a novel solid acid for diverse catalysis.