One of the main challenges limiting the widespread industrial use of absorbent-based CO₂ capture is the energy intensive solvent regeneration, due to poor CO₂ desorption kinetics. The addition of a catalyst can help optimize the CO₂ desorption rate at low temperatures and minimize the thermal dependence of CO₂ desorption reactions. In this work, we report a new class of inexpensive and abundant montmorillonite clay-based catalysts for this purpose, which can be readily tuned by simple ion-exchange with acid or metal solutions. As an example, in this study montmorillonite was ion-exchanged with an acid, H₂SO₄ and a metal, Zr. The ion-exchange process substantially increased the BET surface area (up to 10 times), mesoporosity, and surface acidity of the parent montmorillonite without noticeably destroying the clay structure. Solvent regeneration experiments at the moderate temperature of 86 °C showed that the catalysts are effective at low temperature, and increased the CO₂ desorption rate by up to 215%, the quantity of desorbed CO₂ by up to 79%, and reduced the relative heat duty by up to 44.15% compared to the benchmark amine solution. Additionally, the prepared catalysts could be easily separated by simple filtration, and their stability was confirmed for five cyclic uses. Finally, based on characterizations and experimental results, a plausible reaction mechanism for the ion-exchanged montmorillonite catalyzed CO₂ desorption reaction is also presented.

限制基于吸收剂的CO ₂捕集在工业上的广泛应用的主要挑战之一是由于CO _2的解吸动力学差而导致的能量密集型溶剂再生。催化剂的添加可以帮助优化低温下的CO ₂解吸速率，并使CO ₂解吸反应的热依赖性最小。在这项工作中，我们报告了用于这类目的的新型廉价且丰富的蒙脱土基催化剂，可以通过与酸或金属溶液进行简单的离子交换轻松地对其进行调节。例如，在本研究中，蒙脱石与酸H ₂ SO ₄进行了离子交换。还有一种金属Zr 离子交换过程显着增加了母体蒙脱石的BET表面积（最高达10倍），中孔性和表面酸度，而没有明显破坏粘土结构。在86°C的中等温度下进行的溶剂再生实验表明，该催化剂在低温下有效，并且使CO _2的解吸速率提高了高达215％（解吸的CO ₂量）与基准胺溶液相比，最多可降低79％，并将相对热负荷降低多达44.15％。另外，通过简单的过滤可以容易地分离所制备的催化剂，并且证实了其对于五次循环使用的稳定性。最后，根据表征和实验结果，提出了离子交换蒙脱石催化CO ₂脱附反应的合理反应机理。