Table 1: The d-band centers ( 𝐸 d - b a n d ) , the preferential adsorption sites for H adsorption, and the energies of hydrogen adsorption ( 𝐸 a d s ) on studied surfaces. Both palladium and platinum surfaces are divided by bolded lines in three groups, depending on their exposition to the compressive strain (the first group), the absence of the surface strain (the second group), or the presence of the tensile strain (the third group).

Palladium surfacePlatinum surfaces
Label 𝐸 d - b a n d /eVAdsorption site 𝐸 a d s /eVLabel 𝐸 d - b a n d /eVAdsorption site 𝐸 a d s /eV

PdML/Cu(111)−2.42hcp0.10PtML/Cu(111)−2.82atop0.40
(PtML)2/Cu(111)−2.62atop−0.05
(PdML)2/Cu(111)−2.09fcc−0.16PtML/Pd(111)−2.15fcc−0.38
(PtML)2/Pd(111)−2.42fcc−0.39

Pd(111)−1.71fcc−0.48Pt(111)−2.13fcc−0.43
Cuund/Pd(111)−1.76fcc−0.40Cuund/Pt(111)−2.14fcc−0.18
Ptund/Pd(111)−1.81fcc−0.49Pdund/Pt(111)−2.10fcc−0.41
Auund/Pd(111)−1.63fcc−0.46Auund/Pt(111)−1.91fcc−0.39

PdML/Pt(111)−1.80fcc−0.51PtML/Au(111)−1.75fcc−0.60
(PdML)2/Pt(111)−1.68fcc−0.51
PdML/Au(111)−1.37fcc−0.60(PtML)2/Au(111)−2.02fcc−0.58
(PdML)2/Au(111)−1.50fcc−0.62