Experimental conditions for six experiments designed to reveal the effect of relevant parameters on reaction yield. Conditions 1–3 vary voltage, condition 4 adjusts the alkalinity, and condition 5 does not oxidize the copper before the reaction. All conditions were 30 hour reactions performed inside a fume hood, open-to-atmosphere reaction vessel at room temperature.

Condition	Potential (V vs. RHE)	Concentration of NaOH (M)	Cu electrode oxidation time (min)
1	1.56	1.0	60
2	1.51	1.0	60
3	1.46	1.0	60
4	1.46	0.5	60
5	1.46	1.0	None