Electrochemical Alcohol Oxidation Reaction (AOR)

References

1. NonAqueous AOR

2. Aqueous AOR

2.1. References

Electrochemical Oxidation of Primary Alcohols Using a Co₂NiO₄ Catalyst: Effects of Alcohol Identity and Electrochemical Bias on Product Distribution ACS Catal. 2023, 13, 1, 515–529

2.2. Experiments

2.2.1. Preparing substrate

GCE: 5 mm diameter glassy carbon disks (4 mm thick, 0.196 cm² surface area)^{[ACS Catal. 2023, 13, 1, 515–529]}
The glassy carbon disks were sonicated sequentially in water, isopropanol, and then water for 1 min, ~~and then lapped with silicon carbide abrasive papers (CarbiMet 2, 600/P1200, Buehler)~~. Following a sonication in 1 M nitric acid for 30 min, and then water for 1 min, the electrodes were polished sequentially with diamond abrasive slurries ~~(MetaDi Supreme, Buehler)~~ in an order of 9, 6, 3, 1 μm on synthetic nap-based polishing pads ~~(MD Floc, Struers)~~. Between each polishing step, the electrodes were sonicated for ∼30 s in i-PrOH. The lapping and polishing were performed using a Struers LaboPol-5 polisher with a LaboForce-1 specimen mover. The disks were held in the LaboForce-1 specimen mover with 5 psi of applied pressure per disk, and during lapping and polishing, the platen speed was held at 200 rpm and the head speed at 8 rpm in the opposite rotation direction from the platen. After the final polishing step, the glassy carbon disks were sonicated in aqueous 1 M HNO₃ for 10 min, followed by sequential 3 min sonication steps in acetone and ultrapure water, and then dried in an N₂ stream
GCP: 1.6 cm × 3.2 cm glassy carbon plates (0.1 mm thick, 5.1 cm² surface area)^{[ACS Catal. 2023, 13, 1, 515–529]}

2.2.1. Preparing working electrode

Option 1: Briefly, catalyst ink suspensions were prepared by adding 80 mg of the material powder into a solution of 3.8 mL of H₂O, 1 mL of i-PrOH, and 40 μL of 5 wt % Nafion 117 solution added in that order. Immediately prior to dropcasting, the suspension was sonicated for 30 min to disperse the material powder. The material suspension was dropcast onto the polished glassy carbon surface through two sequential additions of ~~5 μL~~ each using a calibrated micropipette, with continued sonication of the ink solution between additions. Electrodes were dried for 10 min in air at 60 °C after each addition.^{[ACS Catal. 2023, 13, 1, 515–529]} (this reference used either GCE or GCP)
Option 2

2.2.3. Preparing electrolyte

Electrolyte solutions used for oxygen evolution reaction (OER) experiments contained 1 M NaOH in water, and electrolyte solutions used for alcohol oxidation experiments (AOR) contained 1 M NaOH and 100 mM alcohol (EtOH, n-PrOH, n-BuOH, or n-PnOH) in water. For example, to prepare an electrolyte solution for an n-BuOH oxidation experiment, ∼15 mL of 1 M NaOH was added to a 25 mL volumetric flask, followed by the addition of 183 μL of n-BuOH. The flask was then filled to the volume line with 1 M NaOH and mixed vigorously to ensure the dissolution of the n-BuOH.