CONVERSION OF ISOPROPANOL AND CRACKING OF CUMENE OVER NIO-AL2O3 CATALYSTS

NiO-Al2O3 samples of varying composition were prepared from their nitrate solutions using NH4OH. The catalysts were obtained by the thermal treatment, in air, at 450, 550, 650 and 750-degrees-C. X-ray investigation of the thermal products was made. The textural properties of these thermal products were determined from the nitrogen adsorption measurements at 77 K. The surface acidities at 473 and 673 K were measured by the chemisorption of pyridine. The catalytic conversion of isopropanol as well as the catalytic cracking of cumene were measured on NiO-Al2O3 samples at 473 and 673 K respectively. The surface area slightly increased upon rising the calcination temperature from 450-degrees to 550-degrees-C and then continuously decreased upon further rise of the calcination temperature. The mean pore radius showed continuous increase with the increase of the calcination temperature. The surface acidity measured at 473 K decreased with the increase in NiO content. The reverse was found for acidities measured at 673 K. Catalytic dehydration of isopropanol is related to the surface acid density while the dehydrogenation of this alcohol depends on NiO content. The cracking of cumene is related to the N(acid)/g, measured at 673 K.