Co-based heterogeneous catalysts from well-defined α-diimine complexes: Discussing the role of nitrogen

Ar-BIANs and related alpha-diimine Co complexes were wet impregnated onto Vulcan (R) XC 72 R carbon black powder and used as precursors for the synthesis of heterogeneous supported nanoscale catalysts by pyrolysis under argon at 800 degrees C. The catalytic materials feature a core-shell structure composed of metallic Co and Co oxides decorated with nitrogen-doped graphitic layers (NGr). These catalysts display high activity in the liquid phase hydrogenation of aromatic nitro compounds (110 degrees C, 50 bar H-2) to give chemoselectively substituted aryl amines. The catalytic activity is closely related to the amount and type of nitrogen atoms in the final catalytic material, which suggests a heterolytic activation of dihydrogen. (C) 2017 Elsevier Inc. All rights reserved.