Direct synthesis of dimethyl carbonate from CO2 and methanol over trifluoroacetic acid modulated UiO-66

Abstract A series of trifluoroacetic acid (TFA) modulated metal-organic frameworks UiO-66 catalysts were synthesized for the direct synthesis of dimethyl carbonate (DMC) from CO 2 and methanol in this work. Characterization results show that the surface area, pore size, pore volume as well as the amount of missing-linker defects, Lewis acid site, Lewis basic site and hydroxyl of UiO-66-X can be tuned by regulating the amount of TFA modulator. Catalytic activity assessments reveal that TFA modulation enhanced the activity of UiO-66-X. The catalytic activity improvement of the UiO-66-X could be attributed to the increased amount of active sites and the enlargement of porosity originated from TFA modulation. Moreover, a possible reaction mechanism for DMC synthesis from CO 2 and methanol over UiO-66-X was proposed based on the in situ FT-IR results.