Mixtures of carbon and Ni/Al2O3 as catalysts for the microwave-assisted CO2 reforming of CH4

In this work, the microwave-assisted CO₂ reforming of CH₄ over mixtures of carbonaceous materials and an in-lab prepared Ni/Al₂O₃ was studied. Ni/Al₂O₃ is not heated by microwave radiation, and for this reason, microwave receptors, such as carbonaceous materials, must be mixed with this catalyst. In order to evaluate the role of the carbonaceous component of the blend, two different carbonaceous materials were used: an activated carbon, FY5, and a metallurgical coke, CQ. The carbonaceous component acted not only as microwave receptor but also as catalyst and, consequently, it influenced the catalytic activity of the mixture. FY5 + Ni/Al₂O₃ was found to be a better catalyst than CQ + Ni/Al₂O₃, since FY5 on its own showed a better catalytic activity than CQ. Ni/FY5, which consists of Ni impregnated directly onto the microwave receptor, was also evaluated as a catalyst. It was found that the catalytic activity of the mixture FY5 + Ni/Al₂O₃ was better than that of Ni/FY5. Finally, the influence of the heating device on the catalytic activity of FY5 + Ni/Al₂O₃ was studied. Conversions over FY5 + Ni/Al₂O₃ and microwave heating were found to be similar to conversions over Ni/Al₂O₃ and conventional heating.