Abstract Porous two-dimensional materials are potential candidates for the realization of gas separation, which are crucial for developing clean energy sources. Here, we found that CrI3 monolayer which has uniform nanopores around 2.9 A in intrinsic structures can simultaneously fulfill the requirements of both high permeability and high selectivity. Our results show that the diffusion energy barriers of H2 and impurity gases (N2, CO, CO2, H2O and CH4) passing through the nanopores of CrI3 monolayer are 0.27 eV, 1.49 eV, 1.31 eV, 1.54 eV, 0.87 eV and 3.88 eV, respectively, which indicates that these impurity gases hardly pass through the CrI3 monolayer and H2 can be effectively separated from the gases mixture. Also, at the temperature of 300 K, the permeability of H2 (1 × 10−5 mol·m−2·s−1·pa−1) is significantly larger than the minimum acceptable permeability for industry (6.7 × 10−9 mol·m−2·s−1·pa−1). Thus, the CrI3 monolayer is a promised candidate of the hydrogen purification for the future applications.

中文翻译：

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基于第一性原理计算的二维CrI3膜高效氢气净化

摘要 多孔二维材料是实现气体分离的潜在候选材料，对发展清洁能源至关重要。在这里，我们发现在本征结构中具有约 2.9 A 均匀纳米孔的 CrI3 单层可以同时满足高渗透性和高选择性的要求。我们的结果表明，通过 CrI3 单层纳米孔的 H2 和杂质气体（N2、CO、CO2、H2O 和 CH4）的扩散能垒分别为 0.27 eV、1.49 eV、1.31 eV、1.54 eV、0.87 eV 和 3.88 eV，分别说明这些杂质气体很难通过 CrI3 单分子层，H2 可以有效地从气体混合物中分离出来。此外，在 300 K 的温度下，H2 的渗透率（1 × 10−5 mol·m−2·s−1·pa−1）明显大于工业可接受的最小渗透率（6.7 × 10−9 mol·m−2·s−1· pa-1)。因此，CrI3 单层是未来应用中氢纯化的一个有希望的候选者。