Two dimensional Rh/Fe3O4/g-C3N4-N enabled hydrazine mediated catalytic transfer hydrogenation of nitroaromatics: A predictable catalyst model with adjoining Rh

A magnetically separable 2D Rh/Fe 3 O 4 /g-C 3 N 4 -N catalyst has been synthesized for the catalytic transfer hydrogenation of nitroarenes to afford corresponding anilines. The highly dispersed Rh nanoparticles are the dominant active species. The reaction is second order for rhodium according to the kinetic study, and this means the activity of different Rh-containing catalyst can be precisely predicted and the active site contains two adjoining rhodium atoms. The strong interaction between Rh and Fe 3 O 4 contributes to the catalytic performance, therefore the obtained Rh/Fe 3 O 4 /g-C 3 N 4 -N catalyst exhibits excellent catalytic activity and chemoselectivity for the reduction of various nitroaromatics, and the turnover frequencies (TOF) can reach as high as 12,666 h −1 for 4-nitrophenol. Moreover, this catalytic system is environmentally friendly because of its green solvent water and harmless byproducts (H 2 O and N 2 ), and the catalyst shows outstanding stability and recyclability with at least 12 cycles.