Combining co-precipitation-gelation, mechanical mixing and impregnation methods, a series of catalysts of FeK-M/γ-Al 2O 3(M=Cd or Cu) have been attained. The catalysts were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), N 2 physisorption, X-ray diffraction (XRD) and temperature-programmed reduction of hydrogen (H 2-TPR). The hydrogenation of carbon dioxide over these catalysts was also investigated in a fixed bed. Given a reaction time of 100 h, CO 2 conversion over a 15%Fe/10%K/γ-Al 2O 3 catalyst reached 51.3%, with a selectivity towards C 2+ of 62.6% at 3 MPa, 673 K, a space velocity of 3600 h -1 and at a molar ratio of H 2/CO 2 of 3. At the lower Fe content of 2.5%, the selectivity towards C 2+ was still greater than 60.0%. Increasing the potassium content from 0% to 10%, increased the selectivity towards C 2-C = 4 and the molar ratio of C 2-C = 4/C 2-C 0 4 increased to 3.6. The addition of Cd and Cu improved the reduction and catalytic activities. Specifically, Cu improved the molar ratio of C 2-C = 4/C 2-C 0 4 from 3.6 to 5.4, and the Cd increased the selectivity of C 5+ by 12%.
All Science Journal Classification (ASJC) codes
- Physical and Theoretical Chemistry