Chemoselective nitroarene hydrogenation over Ni-Pd alloy supported on TiO2 prepared from ilmenite-type PdxNi1−xTiO3

Abstract

Herein, we prepared TiO2 (rutile)-supported monometallic Ni and bimetallic Pd-Ni catalysts by thermal reduction of PdxNi1−xTiO3 (x = 0 and 0.045) and evaluated their performance for the chemoselective hydrogenation of nitrobenzene under optimized conditions. In contrast to Ni/TiO2, Pd-Ni/TiO2 featured a negligible loss of both conversion and aniline yield over five consecutive catalytic cycles, and instrumental analysis and catalytic activity evaluation revealed that this enhanced stability is due to Pd-Ni-alloy formation. Furthermore, Pd-Ni/TiO2 was used to prepare aromatic-amines used as building blocks for the production of important drugs precursors, achieving conversions of >98 % and a chemoselectivity of 99 % in the absence of undesired side-reactions.