In the present study, long-term electrolysis runs over 6 h are conducted in pulsed mode. Time can not be prolonged for more because of the flooding of the carbon cloth electrode. To prove C-N bond formation in the pulsed electrolysis, the electrolyte after 6h electrolysis was analyzed on a GC 7890A coupled to an MS G3174A (Agilent technologies). The detailed detection method can be found in Supplementary Note 8.