Cu/Al2O3 catalyst prepared by a double hydrolysis method for a green, continuous and controlled N-methylation reaction of nitroarenes with methanol

Cu/Al 2 O 3 catalyst was developed by a double hydrolysis precipitation. Over the Cu/Al 2 O 3 catalyst, a continuous mode of N-methylations of nitroarenes with methanol was successfully achieved under the exogenous base- and H 2 - free condition. Methylation process of nitroarenes could be controlled just by adjusting reaction conditions, affording the desired N-monomethylanilines or N, N-dimethylanilines, respectively. The characterization displayed that the double hydrolysis precipitation method made active metal Cu surface enrichment and high dispersion, meanwhile endow Cu/Al 2 O 3 with more developed pore system, which were responsible for the higher performance of our catalyst relative to Cu/Al 2 O 3 -CP. Compared with the reported batch mode, our procedure possessed the merits of low cost, environment-friendliness, better controllability and wide universality.