Control experiments are conducted for further investigation. Electricity and TPPA are two vital factors in the system since experiments suggest neither Sn 0 nor Li 0 can reduce nitrobenzene. The final product will be azobenzene in the absence of any hydrogen donor rather than further hydrogenolysis. It advises that the hydrogen donor is the key to transferring the coupling product to aniline. A small amount of aniline formation may derive from the trace moisture remaining in the solution which can be seen as a hydrogen source. Meanwhile, water can reproduce through hydrodeoxygenation of nitrobenzene and nitrosobenzene which leads to 7.76% aniline selectivity. When it is as the starting material, it will not be converted which proves the stability of the final product aniline in this system. The reduction of hydrogenation is inhibited by AgNO3, a strong oxidant that acts as an electron scavenger, which indicates the important role of reductive electrons during the reaction.