Figure 5.

EC-MS dissolution profiles showing the signal for m/z = 44, attributed to CO₂, as a function of electrode potential. The electrochemical protocol applied to Au/C in 0.05 M H₂SO₄ consisted of 20 activation cycles (100 mV/s, 0.28–1.58 V_RHE), followed by sets of 20 cycles (100 mV/s) from 0.28 V_RHE to an increasing UPL, namely, 1.31, 1.41, 1.51, and 1.61 V_RHE. This was followed by the AST (500 cycles, 1 V/s, 0.58–1.41 V_RHE) and a 15 min potential hold at 1.41 V_RHE. Sets of cycles were separated by 5 min of open circuit potential to allow for background stabilization.