We report, for the first time, 100% selectivity in the continuous gas phase hydrogenation of m-dinitrobenzene to m-nitroaniline (m-NAN) over Au/Al2O3. The synthesis and application of an alumina supported Au-Ni alloy is also described where alloy formation is demonstrated by XRD, diffuse reflectance UV-Vis and HRTEM analyses. Under the same reaction conditions, Au/Al2O3 delivered a higher (by close to an order of magnitude) hydrogenation rate compared with the alloy. Au-Ni/Al2O3 promoted the formation of both m-NAN and m-phenylenediamine, i.e. partial and complete hydrogenation: the results are consistent with a stepwise reduction mechanism.