Influence of the Fuel Used in the Microwave Synthesis of Cr2O3

Abstract

The synthesis and physico-chemical characterization of chromium oxide (Cr₂O₃) is reported. Samples were prepared by a novel microwave technique using two different fuels, i.e., tetraformaltrisazzine (TFTA) and urea. The physical characterization of the synthesized chromium oxides was achieved using XRD, IR, Raman, BET surface area and pore size distribution (PSD) techniques. The XRD and IR and Raman spectroscopy studies reveal that crystalline Cr₂O₃ is the only phase formed. The XRD, surface area and particle size analysis reveal that the samples prepared using TFTA as the fuel possess a larger surface area, smaller crystalline size, smaller particle size and larger pore diameter. Both samples were calcined at 600 °C for 6 h so that they could be used for the catalytic oxidation of LPG. Catalytic runs on the Cr₂O₃ samples revealed that the two samples possess different activity and selectivity. The Cr₂O₃ sample prepared by using TFTA as the fuel gave rise to more dehydrogenation and cracking compared to the sample prepared by using urea as the fuel, which gave more combustion products.