Figure shows the results from controlled potential electrolysis of AP at -0.48 VRHE over 5 h under stirring (10 mL of solution containing 0.5 mmol AP, electrode surface area = 0.84 cm 2 ), where the reaction mixture was analyzed by 1 H-NMR spectroscopy (Supplementary Figure ) every hour to quantify the amounts of AP and 1-PEA in the solution. After 5 h, a yield of 91±1% was achieved for 1-PEA, and the AP remaining in the electrolyte solution was only 7.3±4%. The FE1-PEA was higher than 60% in the first 3 h of electrolysis, and still maintained at 47±6% when the conversion was finished after 5 h. The ECH of AP was also investigated on Ag, Au, In, Pt and Ni electrocatalysts (Supplementary Figure shows the morphologies) at -0.48 VRHE for 1 h (Fig. ). Ag and Au exhibited high FE1-PEA (80-90%) and J1-PEA (10-15 mA cm -2 ) values, whereas In and Pt showed much lower performances (i.e. FE1-PEA ~20% and J1-PEA ~2.5 mA cm -2 ) and Ni did not show any ECH activity. These results collectively demonstrate the efficient ECH of AP to 1-PEA on Cu, Ag and Au, as predicted by computational surface coverage studies.