Noble　metal　nanoporous　materials　hold　great　potential　in　the　field　of　catalysis,　owing　to　their　high　open　structures　and　numerous　low　coordination　surface　sites.　However,　the　formation　of　porous　nanoparticles　is　restricted　by　particle　size.　Herein,　we　utilized　a　Pt1Bi2　intermetallic　nanocatalyst　to　develop　a　dealloying　approach　for　preparing　nanoparticles　with　a　bi-continuous　porous　and　core-shell　structure　and　proposed　a　mechanism　for　the　formation　of　pores.　The　particle　size　used　to　form　the　porous　structure　can　be　＜10　nm,　which　enhances　the　nanocatalyst＇s　performance　for　the　oxygen　reduction　reaction　(ORR).　This　study　provides　a　new　understanding　of　the　formation　of　porous　materials　via　a　dealloying　approach.