Nickel foam (99.99%; MTI) electrodes were prepared from 10×15 mm rectangle flags. The electrode flags were mechanically connected to a Ni bus wire via a crimping barrel. The bus wire was passed through a glass tube, then the pressed section of the foam, wires, and glass tube end was sealed using a chemically stable two-part epoxy adhesive (Loctite 9460) and cured for at least 24 hours prior to use. The geometric area of each nickel foam electrode was 1 cm 2 . GEOR electrocatalysts were fabricated on Ni foam electrodes as described in previous work. The foam was first rinsed with acetone, methanol, isopropyl alcohol, and water in sequence, then dried using a stream of nitrogen. This was done to remove any possible organic residue from the surface of the electrode. The electrodes were then placed in a 1 N HCl solution for 10 minutes to remove the native nickel oxide layer. After rinsing with water, gold and platinum were deposited in sequence on the clean nickel foam electrode by the galvanic replacement reaction. First, the nickel foam was placed in a gold deposition solution (0.4 mM NaAuCl4 in 10.0 mM H2SO4) for 5 minutes, then rinsed with water, then placed in a platinum deposition solution (0.6 mM K2PtCl4 in 10.0 mM H2SO4) for 5 minutes. The Au-Pt-coated electrode was then rinsed with water and placed in an electrochemical cell containing a 1.0 mM Bi(NO3)3 in 1.0 M nitric acid solution, a graphite rod as a counter electrode, and a Ag/AgCl reference electrode. A layer of bismuth was electrodeposited onto the Au-Pt-coated Ni foam electrode at -15.0 mA cm -2 for 5 seconds, producing an Au-Pt-Bi-coated Ni electrode for the GEOR electrocatalysis. Detailed analysis of the structure and chemical composition and analysis of the Au-Pt-Bi-coated Ni electrodes can be found elsewhere. Pt-coated Ni foam electrodes used for HER and OER were fabricated by placing the rinsed and dried Ni foam electrodes in a 0.6 mM K2PtCl4 solution for 10 minutes.