. 2023 Nov 1;14:6994. doi: 10.1038/s41467-023-42794-2

Table 1.

The list of control experiments carried out to elucidate the mechanistic pathway towards urea at –0.5 V for 2 h

Entry	C-source	N-source	Urea?	Electrolyte solution
1	CO₂	KNO₃	√	100 mM KNO₃
2	HCOOH	KNO₃	√	100 mM KNO₃ + 20 mM HCOOH
3	HCHO	KNO₃	×	100 mM KNO₃ + 20 mM HCHO
4	CH₃OH	KNO₃	×	100 mM KNO₃ + 20 mM CH₃OH
5	CO	KNO₃	√	20 mM KNO₃
6	KHCO₃ + CO₂	KNO₂	√	20 mM KNO₂ + 100 mM KHCO₃
7	KHCO₃ + CO₂	NH₂OH	√	20 mM NH₂OH + 100 mM KHCO₃
8	KHCO₃ + CO₂	HCONH₂	√	20 mM HCONH₂ + 100 mM KHCO₃
9	KHCO₃ + CO₂	NH₃	×	20 mM NH₃ + 100 mM KHCO₃
10	KHCO₃ + CO₂	NH₄Cl	×	20 mM NH₄Cl + 100 mM KHCO₃