Potassium bicarbonate khco3

Ethanol
(C₂H₅OH) (200
proof) and potassium bicarbonate (KHCO₃) were purchased
from Sigma-Aldrich. Deionized (DI) water (18.2 MΩ cm) produced
by an ultrapure purification system (Milli-Q advantage A10) was used
to make the solutions. Pc-Cu was purchased from Sigma-Aldrich with
99.999% purity. The Nafion 115 membranes were purchased from the Fuel
Cell Store. All reagents were used as received without further purification.

All the chemicals, including selenium powder (200 mesh, 99.5%, Acros Organics), nickel(II) acetylacetonate (Ni(acac)₂, 96%, Sigma–Aldrich), OAm (80–90%, Acros Organics), OAc (99%, Sigma–Aldrich), KOH (85%, Sigma–Aldrich), potassium carbonate (K₂CO₃, 99.5%, Sigma–Aldrich), potassium bicarbonate (KHCO₃, 99.7%, Sigma–Aldrich), ODE (90%, Sigma‐Aldrich), DDT (98%, Sigma–Aldrich), carbon black (CB, Vulcan XC72, Sigma–Aldrich), EG (99.8%, Sigma Aldrich), and Nafion (10 wt%, perfluorinated ion‐exchange resin, dispersion in water, Sigma–Aldrich), were used as received, without further treatment. Analytical grade chloroform and ethanol for the washing process were obtained from various sources. MilliQ water (18.2 MΩ cm) was used for the preparation of electrolyte and catalytic ink, and IC measurements. An argon‐filled glove box was used to handle sensitive chemicals and reactive ink preparation during the synthesis.