Quaternary Hydrides Pd_1-y-zAgyCu_zH_x Embedded Atom Method Potentials for Hydrogen Energy Applications

The Pd-H system has attracted extensive attention. Pd can absorb considerable amount of H at room temperature, this ability is reversible, so it is suitable for multiple energy applications. Pd-Ag alloys possess higher H permeability, solubility and narrower miscibility gap with better mechanical properties than pure Pd, but sulfur poisoning remains an issue. Pd-Cu alloys have excellent resistance to sulfur and carbon monoxide poisoning and hydrogen embrittlement, good mechanical properties, and broader temperature working environments over pure Pd, but relatively lower hydrogen permeability and solubility than pure Pd and Pd-Ag alloys. This suggests that alloying Pd with Ag and Cu to create Pd-Ag-Cu ternary alloys can optimize the overall performance and substantially lowers the cost. Thus, in this paper, we provide the first embedded atom method potentials for the quaternary hydrides Pd_1-y-zAgyCu_zH_x. The fully analytical potentials are fitted utilizing the central atom method without performing time-consuming molecular dynamics simulations.