Electronic Supplementary Information (ESI) for Electrochemical CO2 reduction over nanoparticles derived from oxidized Cu-Ni intermetallic alloy

Experimental section Materials All starting materials were used as-received. Hexane and potassium bicarbonate (KHCO3) were purchased from Fujifilm Wako Pure Chemical Corp. Potassium bicarbonate-13C (KH13CO3, 98 at% 13C) was purchased from Isotec Inc. Carbon paper (CP; TGP-H-060) was purchased from Toray Industries, Inc. Cu foil (99.9%, thickness: 0.08 mm) and cupronickel (Cu:Ni=70:30, thickness: 0.3 mm) foil were purchased from Nilaco Corp.