Influence of N addition in mesoporous carbons used as supports of Pt, Pd and Ru for toluene hydrogenation and iron oxide for benzene oxidation

摘要

Two catalysts series, one with precious metals (Pt, Pd and Ru) and the other with Fe oxide supported on three kinds of mesoporous carbon materials (MC: mesoporous carbon, N-MC: N-containing MC, C3N4-MC: MC with supported carbon nitride) were prepared by an impregnation method. They were characterized by low-temperature adsorption/desorption isotherms of nitrogen, X-ray diffraction, transmission electron micrograph, X-ray photoelectron spectroscopy, and H-2-temperature programmed reduction. The results indicate that a better metal dispersion and a higher reducibility can be found on N-containing catalysts. Precious metal catalysts were applied in toluene hydrogenation, while iron oxide catalysts were applied in benzene oxidation to phenol. The results show that the presence of N in the MC support leads to an important increase in toluene conversion using Ru catalysts at 373 K. On the contrary, N introduction created a negative effect in benzene oxidation to phenol on supported iron catalysts.