Quantification of Hydride Coverage on Cu(111) by Electrochemical Mass Spectrometry
EC-MS combined with chronoamperometry quantifies the Cu(111) surface hydride phase in H₂SO₄, tracking H₂ production to partition reduction current between anion desorption, hydride formation, and HER. Saturated hydride coverage of 0.67 is established, with thin-layer cell geometry enabling total H₂ collection to overcome diffusional delay in the EC-MS response.