The　plastic　waste　issue　has　posed　a　series　of　formidable　challenges　for　the　ecological　environment　and　human　health.　While　conventional　recycling　strategies　often　lead　to　plastic　down-cycling,　the　electrochemical　strategy　of　recovering　valuable　monomers　enables　an　ideal,　circular　plastic　economy.　Here　a　corrosion　synthesized　single　atom　Pt1/Ni(OH)2　electrocatalyst　with　part-per-million　noble　Pt　loading　for　highly　efficient　and　selective　upcycling　of　polyethylene　terephthalate　(PET)　into　valuable　chemicals　(potassium　diformate　and　terephthalic　acid)　and　green　hydrogen　is　reported.　Electro-oxidation　of　PET　hydrolysate,　ethylene　glycol　(EG),　to　formate　is　processed　with　high　Faraday　efficiency　(FE)　and　selectivity　(＞90%)　at　the　current　density　close　to　1000　mA　cm-2　(1.444　V　vs　RHE).　The　in　situ　spectroscopy　and　density　functional　theory　calculations　provide　insights　into　the　mechanism　and　the　understanding　of　the　high　efficiency.　Remarkably,　the　electro-oxidation　of　EG　at　the　ampere-level　current　density　is　also　successfully　illustrated　by　using　a　membrane-electrode　assembly　with　high　FEs　to　formate　integrated　with　hydrogen　production　for　500　h　of　continuous　operation.　This　process　allows　valuable　chemical　production　at　high　space-time　yield　and　is　highly　profitable　(588-700　$　ton-1　PET),　showing　an　industrial　perspective　on　single-atom　catalysis　of　electrochemical　plastic　upcycling.