Cohesion properties and hydrogen permeation at PdCu/TiAl interface

•BCC PdCu/TiAl interfaces seem thermodynamically more stable than that of FCC PdCu/TiAl interfaces.•Hydrogen solubility of the six PdCu/TiAl interfaces is lower than that of corresponding PdCu bulk due to the higher binding energy.•FCC PdCu(001)/TiAl(100) and FCC PdCu(100)/TiAl(100) interfaces have higher hydrogen diffusivity than FCC PdCu bulk as a result of the lower activation energy.•for FCC PdCu(100)/TiAl(100) and FCC PdCu(001)/TiAl(100) interfaces, the decrease of hydrogen permeability should be primarily ascribed to the lower hydrogen solubility, rather than hydrogen diffusivity.