Zou Changlong, Deng Xuepeng, Han Yang, Lin Li-Chiang
William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, 151 West Woodruff Avenue, Columbus, Ohio 43210-1350, United States.
Department of Chemical Engineering, National Taiwan University, No.1, Sec. 4 Roosevelt Rd., Taipei 106319, Taiwan.
J Phys Chem C Nanomater Interfaces. 2025 May 11;129(20):9550-9561. doi: 10.1021/acs.jpcc.5c01717. eCollection 2025 May 22.
The pressing need to address climate change has led to significant advancements in carbon dioxide (CO) capture technologies. Notably, facilitated transport membranes (FTMs) are distinguished by their exceptional selectivity and permeance, attributed to their reversible chemical reactions with CO. This study, for the first time, sheds light on the reactive diffusion mechanism of CO in FTMs, utilizing 1,1,3,3-tetramethylguanidine (TMG) as a mobile carrier. Specifically, state-of-the-art molecular dynamics (MD) simulations, augmented by a reparameterized reactive force field (ReaxFF) capable of describing atomistic interactions and reaction pathways, are conducted to investigate the transport of CO in TMG. The analysis of mean squared displacement (MSD) and diffusion coefficients reveals a clear hierarchy in the mobility of reaction components. Our findings highlight a unique hopping diffusion mechanism between bicarbonate ions and TMG molecules, increasing the diffusivity of reacted CO by 1.4 times. The hopping events observed not only enhance our understanding of molecular mobility but also offer a means to boost the performance of FTMs in CO capture applications. Overall, this research lays the groundwork for the future design of FTMs with optimal carrier properties.
应对气候变化的迫切需求推动了二氧化碳（CO）捕集技术的重大进展。值得注意的是，促进传递膜（FTMs）因其与CO的可逆化学反应而具有卓越的选择性和渗透性。本研究首次利用1,1,3,3-四甲基胍（TMG）作为移动载体，揭示了CO在FTMs中的反应扩散机制。具体而言，通过能够描述原子相互作用和反应途径的重新参数化反应力场（ReaxFF）增强的先进分子动力学（MD）模拟，来研究CO在TMG中的传输。对均方位移（MSD）和扩散系数的分析揭示了反应组分迁移率的明显层次结构。我们的研究结果突出了碳酸氢根离子与TMG分子之间独特的跳跃扩散机制，使反应后的CO扩散率提高了1.4倍。观察到的跳跃事件不仅增进了我们对分子迁移率的理解，还为提高FTMs在CO捕集应用中的性能提供了一种方法。总体而言，本研究为未来设计具有最佳载体性能的FTMs奠定了基础。
