Theoretical investigations of permeability and selectivity of Pd-Cu and Pd-Ni membranes for hydrogen separation

Hydrogen is one of the most prospective energy resources with zero polluted emission and high energy utilization, an improved separation and purification performance of hydrogen is critical for application of hydrogen energy. In this work, hydrogen separating performance of Pd-Cu and Pd-Ni alloy membranes are theoretically explored through density functional theory and molecular dynamics calculations. The results demonstrate that both Pd-Cu and Pd-Ni membranes exhibit excellent selectivity to H-2 over N-2, CO, CO2, CH4, H2S at varied temperatures, and are superior to industrial production limit based on predicting permeance of H-2. The outstanding selectivity of Pd-Cu alloy toward H-2 is in accordance with experimental conclusion. Moreover, the DFT calculations are further supported by molecular dynamics simulations, which visually demonstrate the H-2 separation performance of the Pd-based alloys in a dynamic way. This work provides an effective and efficient approach to evaluate the permeability and selectivity of metal alloys membranes for gas separation. (C) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

This study theoretically explored the hydrogen separation performance of Pd-Cu and Pd-Ni alloy membranes, which exhibit superior selectivity to H-2 over N-2, CO, CO2, CH4, and H2S at varied temperatures, surpassing industrial production limits. Experimental conclusions are consistent with density functional theory calculations, further supported by molecular dynamics simulations.