Hydrogenation of Carbon Dioxide to C 2 –C 4 Hydrocarbons Catalyzed by Pd(P t Bu 3 ) 2 –FeCl 2 with Ionic Liquid as Cocatalyst

Direct hydrogenation of CO 2 to C 2+ hydrocarbons is very interesting, but achieving this transformation below 200 °C is challenging and seldom reported. Herein, a homogeneous catalytic system was developed composed of the ionic liquid 1‐butyl‐3‐methylimidazolium hexafluorophosphate ([BMIm][PF 6 ]), Pd(P t Bu 3 ) 2 , FeCl 2 , and the ligand 4,5‐bis(diphenylphosphino)‐9,9‐dimethylxanthene (Xantphos) for hydrogenation of CO 2 under mild conditions, which resulted in C 2 –C 4 hydrocarbons in selectivities up to 98.3 C‐mol % at 180 °C. The combination of [BMIm][PF 6 ]) with Xantphos endowed the Pd–Fe catalysts with the ability of activating CO 2 and H 2 simultaneously via [HPd(P t Bu 3 )(BMIm‐COO)(BMIm)(PF 6 )Fe] + species, thus catalyzing the formation of C 2 –C 4 hydrocarbons through CO 2 hydrogenation. In addition, this catalytic system is stable and recyclable, which may have promising applications.