Effect of Calcination and Reduction Temperatures on the Reduction and Activity of Boron-modified Co/TiO2 Fischer-Tropsch Catalys

The effect of calcination and reduction temperatures on the reducibility, dispersion and Fischer-Tropsch activity of 10 wt% cobalt supported on titania catalyst modified by 0.1 wt% boron has been studied. The percentage reduction and percentage dispersion were found to decrease with increasing calcination temperature. The higher calcination temperatures decreased the total CO hydrogenation activity, but did not affect the turnover frequency. The decrease in CO hydrogenation rate with increasing calcination temperature is attributed to a decrease in the number of surface active sites. The higher reduction temperature also decreased the total activity. This may be due to the loss of the surface active sites, caused by blocking of the TiOc phases produced at higher reduction temperatures. The higher calcination temperature shifted the F-T product spectrum to the lower weight hydrocarbons. The reduction temperature did not affect the product selectivity. South African Journal of Chemistry Vol.57 2004: 49-5