Table 1. Characteristics of the different NGMs with the total current densities (jtot) and faradaic efficiencies (FE) for each product over the different NGM/CP electrodes at an applied potential of –1.400 V in bulk [Bmim]BF4 with an electrolysis time of 5 h. NT stands for the total N content. NS is the surface N content detected by XPS. SBET stands for the specific surface area.
| Entry | Electrodes | N-Containing base | NT/% | NS/% | S BET/m2 g–1 | j tot/mA cm–2 | FECH4/% | FECO/% | FEH2/% |
| 1 | CP | — | — | — | — | 0.65 | 0 | 29.4 ± 0.4 | 70.5 ± 0.7 |
| 2 | Graphene/CP | — | 0 | 0 | — | 0.87 | 0 | 32.4 ± 1.9 | 67.5 ± 1.4 |
| 3 | NGM-1/CP | 3-Pyridinecarbonitrile | 9.46 | 6.52 | 1.28 | 1.42 | 93.5 ± 1.2 | 4.2 ± 0.2 | 2.1 ± 0.5 |
| 4 | NGM-2/CP | 3-Hydroxypyridine | 6.07 | 4.34 | 1.24 | 1.36 | 81.6 ± 1.5 | 5.7 ± 0.6 | 12.5 ± 0.7 |
| 5 | NGM-3/CP | 4-Dimethylaminopyridine | 4.71 | 3.74 | 1.09 | 1.32 | 67.2 ± 0.4 | 8.6 ± 1.3 | 24.6 ± 0.2 |
| 6 | NGM-4/CP | Benzimidazole | 4.03 | 3.34 | 0.88 | 1.27 | 49.3 ± 0.2 | 24.5 ± 0.4 | 26.1 ± 1.5 |
| 7 | NGM-5/CP | 1-Vinylimidazole | 3.63 | 3.17 | 0.64 | 1.26 | 20.8 ± 1.6 | 56.2 ± 0.3 | 23.1 ± 0.8 |