The role of carbon dioxide in chemoselective hydrogenation of halonitroaromatics over supported noble metal catalysts in supercritical carbon dioxide

Chemoselective hydrogenation of halogenated nitrobenzenes over Pt/C catalysts proceeds effectively in supercritical carbon dioxide (scCO(2)) to produce halogenated anilines with excellent selectivity; the rate of the hydrogenation of nitro groups is markedly enhanced in scCO(2) compared to the neat reaction, and the dehalogenation reaction is significantly suppressed.