Superconductivity of platinum hydride

We report the ac magnetic susceptibility, electrical resistance, and x-ray diffraction measurements of ${\mathrm{PtH}}_{x}\phantom{\rule{4pt}{0ex}}(x\ensuremath{\simeq}1)$ in diamond anvil cells, that reveal the superconducting transition. At 30 GPa, when ${\mathrm{PtH}}_{x}$ is in a ${P6}_{3}/mmc$ structure, ${\mathrm{PtH}}_{x}$ exhibits the superconducting transition at 7 K. Remarkably, the observed ${T}_{c}$ is higher than that of powdered Pt by more than three orders of magnitude. It is suggested that the noble metals in the periodic table of elements possibly form a region where hydrides have higher ${T}_{c}$ than elements.