Abnormal Hydrogen Absorption/Desorption Properties of Nanoporous Pt with Large Lattice Strains

Hydrogen absorption/desorption properties of nanoporous Pt fabricated by dealloying were investigated. At high pressure (> 1.3 MPa), the nanoporous Pt released hydrogen during hydrogen pressurization; in contrast, it absorbed hydrogen up to 3.5 atom% during hydrogen depressurization, which have not been seen in current metal/hydride systems including nanoparticles. First-principles calculations suggested that the abnormal hydrogen absorption/desorption properties are due to the relaxation/preservation of the lattice strain in Pt hydride. [doi:10.2320/matertrans.M2010403]