Catalytic hydrogenation of CO2 to methanol in a Lewis pair functionalized MOF

Capture and conversion of CO2 to methanol using a renewable source of H-2 is a promising way to reduce net CO2 emissions while producing valuable fuels. Design of an efficient heterogeneous catalyst for CO2 hydrogenation is critical for the large-scale implementation of the CO2 to methanol process. Combining both capture and conversion of CO2 in a single material has the potential to reduce the overall cost through process intensification. We have used density functional theory to computationally design a catalyst capable of producing methanol from CO2 and H-2, including calculating the reaction pathways and barriers of each step. The catalyst consists of a microporous metal organic framework ( UiO-67) functionalized with catalytically active Lewis pair functional groups. Our calculations indicate that this novel catalyst facilitates the heterolytic dissociation of H-2 to generate hydridic and protic H atoms bound to Lewis acid and base sites, respectively, which facilitates a series of simultaneous transfer of two hydrogens to produce methanol: CO2 ->(+H2) HCOOH ->(+H2) CH2(OH)(2) ->(-H2O) CH2O ->(+H2) CH3OH. Importantly, our catalyst binds H-2 more strongly than CO2, which prevents CO2 from poisoning the Lewis acid and base sites.