▎ 摘　　要

Designing a highly selective and fast separation membrane is critical to realize H-2-sieving with efficient performance, which is still a challenge by far. In this study, we combine molecular dynamics (MD) and first-principle approaches to investigate the H-2 separation property of graphene crown ether. Our MD results demonstrate that graphene crown ether exhibits a superior H-2-sieving performance under various temperatures and external pressures, allowing fast passage for H-2 while completely rejecting CH4. The H-2 permeability exceeds 10(5) GPU at selectivities exceeding 1500. These results highlight an outstanding performance of crown ether pores for separating H-2 from mixtures with CH4. Observed from MD simulation trajectories, this highly selective separation is caused by the intrinsic dimensional difference between the two types of gases and the pore. The first-principle calculations further confirm that it is energetically more favorable for H-2 to transit the graphene crown ether than for CH4. Our findings suggest a novel application of the graphene crown ether in H-2-sieving with great promise for future membrane designs. (C) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.