Catalytic conversion of CO2 to high value and high energy density chemicals makes CO2 a valuable source of carbon but requires significant energy inputs. Abundant shale gas deserves makes CH4 an ideal hydrogen and energy source for CO2 conversion. However, difficulty in selectively breaking the C−H bonds in CH4 and simultaneously activating CO2 presents a formidable challenge. Recently, direct C−C coupling of CH4 and CO2 has been predicted theoretically and confirmed experimentally. However, designing an active catalyst that activates CO2 simultaneously with selective dissociation of CH4 is critical to achieve co-conversion of CO2 and CH4. Herein, we combine the selectivity of ZnO for CH4 activation and the activity of In2O3 for CO2 activation and design a ZnO/In2O3 catalyst. In this catalyst, the Zn site in ZnO cluster serves as active center for C−H bond activation and stabilizing CH3* while CO2 is activated on In2O3. The coupling of CH3* and CO2* on ZnO/In2O3 follows a four-centered Zn-C-C-O moiety, making the conversion of CH4 and CO2 follow a Langmuir-Hinshelwood mechanism. The results based on density functional theory calculations show that the simultaneous activation of CH4 and CO2 depend on the synergy between the supported ZnO and In2O3. These findings provide a new approach to produce C2 oxygenates effectively by using both CO2 and CH4 as C1 building blocks.

Co-activation of CO2 and CH4 on ZnO/In2O3 for direct C-C formation

256th National Meeting (2018)

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