Rate equation of steam-methane reforming reaction on Ni-YSZ cermet considering its porous microstructure

Abstract

The steam-methane reforming reaction on a Ni-YSZ (yttria-stabilized zirconia) cermet was experimentally investigated in the temperature range of 650 to 750°C. We examined the effects of the partial pressures of methane and steam in the supply gas on the reaction rate. The porous microstructure of the Ni-YSZ cermet was quantified using an FIB-SEM technique. A power-law-type rate equation was obtained on the basis of the unit surface area of the Ni-pore contact surface in the cermet. The kinetics indicated a strong positive dependence on the methane partial pressure and a negative dependence on the steam partial pressure, in good agreement with the literature. The obtained rate equation successfully predicted the reaction characteristics of Ni-YSZ cermets having different microstructures.