“…Sintering of Co and Mo species during the pre-sulfidation and methanation reaction can cause the decrease of specific surface area. 9 However, the addition of 5%CoO to MoO3/Al2O3 catalyst resulted in a decrease in BET specific surface area, and an increase in pore volume and pore size, which was in agreement with the results of Hagiwara et al 24 This may be due to the association of Co species with Mo and alumina that affects the physical property of catalyst.…”