Interestingly, the solvent has a great influence on the reduction of nitrobenzene. In the solvent range of Table1 Entry 4~10, only when the solvent is alcohols (Entry 4、5, and 10) can catalyst have a reduction effect on nitrobenzene. To explore whether hydrogen and methanol are used as a common source of hydrogen, we conducted a set of control experiments (Entry 11). The reductive amination of nitrobenzene was carried out with methanol as a solvent under a nitrogen pressure of 0.8 bar. It was found that no product aniline was formed, which shows that H2 is true as the only hydrogen source. The solvent can not only promote the dispersion of the reactants and enhance the mass transfer process in the catalytic reaction but also change the path of the reaction kinetics . The significant difference in reactivity is only due to the difference in solvation of adsorbed hydrogen. In addition, the polarity of solvent can effectively adjust the bonding between reactant/ intermediate and Pd . The hydrogenation kinetics of nitro compounds on palladium catalyst supported on coal was studied . Klyuev found that the hydrogenation of nitrobenzene is a first-order reaction for catalyst and hydrogen, and a pseudo-zero-order reaction for nitrobenzene. So the significant influence of the solvent is assumed to be due to the sol pores changing the adsorption configuration of reducing groups on the transition metal surface , Changed the potential energy field formed by the hydrogen bond between the original solvent and the organic matrix . It can be concluded that the hydrogen bond with the metal is weaker to a certain extent, which is beneficial to the hydrogenation rate, and it is consistent with the phenomenon in the pressure screening process. In addition to the screening of reaction conditions, we also prepared some catalysts for control reactions. The results showed that although the amount of active metal Pd was reduced to 10% equivalent of Pd@N/C catalyst, the catalytic hydrogenation activity of p-nitrobenzene was greatly improved due to the bimetallic catalytic effect of transition metal Fe. However, when pure Fe was used as the active center, no matter what the valence state of the Fe central atom is, the catalytic hydrogenation of p-nitrobenzene cannot be exerted. Therefore, both Pd and Fe metals play an indispensable role and greatly improve the catalytic activity while reducing the content of the noble metal Pd to a great extent. We have also studied many halogen-substituted and aliphatic nitro compounds and obtained target products with excellent selectivity (Figure ). Both industrially relevant and structurally challenging nitrobenzene derivatives have achieved effective amination, and the corresponding aniline has been produced in good to excellent yields. Fluoride and chloride substrates are well tolerated, aliphatic nitro compounds can also withstand the reaction conditions, and the corresponding anilines can be obtained with excellent yields. Even cycloalkyl nitro compounds with various ring sizes can be successfully transferred to aniline.