Li Gen, Tao Yong, Zhu Xinping, Gao Yining, Shen Peiliang, Yin Binbin, Dupuis Romain, Ioannidou Katerina, Pellenq Roland J-M, Poon Chi Sun
Department of Civil and Environmental Engineering, and Research Centre for Resources Engineering towards Carbon Neutrality, The Hong Kong Polytechnic University, Hong Kong, China.
Laboratoire de Mécanique et Génie Civil, CNRS and Université of Montpellier, Montpellier, France.
Nat Commun. 2024 Dec 30;15(1):10790. doi: 10.1038/s41467-024-55125-w.
The feasibility of carbon mineralization relies on the carbonation efficiency of CO-reactive minerals, which is largely governed by the water content and state within material mesopores. Yet, the pivotal role of confined water in regulating carbonation efficiency at the nanoscale is not well understood. Here, we show that the maximum CO intake occurs at an optimal relative humidity (RH) when capillary condensation initiates within the hydrophilic mesopores. At this transition state, the pore becomes filled with metastable low-density water, providing an ideal docking site for CO adsorption and forming a mixed metastable state of water/CO. We prove that RH depends on the mesopore size through a Kelvin-like relationship, which yields a robust engineering model to predict RH for realistic mineral carbonation. Building upon classical theories of phase transition in hydrophilic mesopores, this study unveils the capacity of the metastable water in CO intake and enhances the high-efficiency carbon mineralization with natural ore and industrial wastes in real-world applications.
碳矿化的可行性依赖于与CO反应性矿物的碳酸化效率，而这在很大程度上受材料中孔内的含水量和状态控制。然而，受限水在纳米尺度上调节碳酸化效率的关键作用尚未得到充分理解。在此，我们表明，当亲水中孔内开始发生毛细凝聚时，最大CO摄入量出现在最佳相对湿度（RH）下。在这个过渡状态下，孔中充满了亚稳态的低密度水，为CO吸附提供了理想的对接位点，并形成了水/CO的混合亚稳态。我们证明，RH通过类似开尔文的关系取决于中孔尺寸，这产生了一个强大的工程模型来预测实际矿物碳酸化中的RH。基于亲水中孔相变的经典理论，本研究揭示了亚稳态水在CO摄入方面的能力，并在实际应用中提高了天然矿石和工业废料的高效碳矿化。
