Dual doping effects (site blockage and electronic promotion) imposed by adatoms on Pd nanocrystals for catalytic hydrogen production.

Three distinctive doping effects to modify the electronic and geometric properties of Pd nanocrystals for HCOOH decomposition to H2/CO2 are presented: Bi atoms take preferable residence on higher index sites, which leads to a reduction in HCOOH dehydration; Te atoms dwell favourably on terrace sites, which reduces the rate of dehydrogenation; Ag atoms, without site specificity, induce strong electronic effects to promote the activity on the dwindling number of surface Pd sites at high coverage.