Interaction of nitromethane with MoO3/SiO2 and its influence on toluene nitration

Interactions of nitromethane with MoO3/SiO2 were investigated by infrared spectroscopy. It was found that nitromethane is adsorbed on the catalyst surface and the unique interactions between the molecules and surface species occur. It hinders surface reactions to occur. It is probable that nitromethane hinders diffusion of HNO3 molecules and NO2+ cations to MoO3/SiO2 surface and pores in the nitration, but does not hinder diffusion of H+ and H2O molecules between solid catalyst phase and solution liquid phase. As a result, the MoO3/SiO2/nitromethane system is effective and selective to isomer ortho-nitrotoluene.

► Interactions between nitromethane and MoO3/SiO2 may be investigated by FT-IR.
► Nitromethane is adsorbed on the MoO3/SiO2 surface.
► Nitromethane adsorption does not interfere with effective H+ generation.
► HNO3/MoO3/SiO2/nitromethane is an ortho-selective nitration system.