Enhancements in nickel-catalyzed hydrogasification of carbon by surface treatments

A pitch coke was given 4 types of pretreatment to modify the surface state; air oxidation, heatingquenching, steam treatment and hydrogen treatment. The treated cokes were impregnated with nickel and gasified in an atmospheric hydrogen flow. The catalytic reactivity of the pitch coke was enhanced by these pretreatments. Several properties of pretreated cokes were compared and it seemed that highly hydrophilic or acidic surfaces of carbon were unfavorable to metal-catalyzed hydrogasification. The reactivity enhancement was ascribed to an increase in the hydrogen adsorption capacity of nickel on the pretreated coke. The oxygen-containing surface groups are presumed to inhibit the spillover of atomic hydrogen from nickel to carbon. The effect of 1 type of pretreatment. heating-quenching, seems to relate to the expansion in pore volume.