For the pulsed electrolysis, the change of FE over time is determined as follows. The time basis for the calculation is one pulse loop consisting of an anodic (time interval tan) and a cathodic (time interval tca) section. All the gas product such as H2, CO, CH4 only form during the cathodic potential. Thus, only invested cathodic charge Qc needs to consider and it is determined by the integration of the current in the cathodic section over time.