Effects of MoO 3 loading and calcination temperature on the catalytic performance of MoO 3 /CeO 2 toward sulfur-resistant methanation

Effect of Citric Acid on MoO3/Al2O3 Catalysts for Sulfur-Resistant Methanation

“…Obviously, the lack of a crystalline MoO 3 peak indicates that MoO 3 is dispersed better as an amorphous form on the Al 2 O 3 supports modified by citric acid. Otherwise, according to our previous study [17], the Al 2 (MoO 4 ) 3 phase can be formed, as the MoO 3 loading exceeded the saturated monolayer coverage with calcination temperatures of 600 • C. Therefore, the disappearance of Al 2 (MoO 4 ) 3 should be attributed to the change in the catalyst saturated monolayer coverage. Combined with the increase in BET surface area and the average pore volume from the N 2 -physisorption results, it can be concluded that the saturated loading capacity of the catalyst can be improved when citric acid is added.…”

“…In our previous study [17], the tetrahedrally coordinated Mo 6+ was proven to be an active catalytic precursor for sulfur-resistant methanation. Based on the variation trend of S t /S o for different catalysts from the Raman result in Table 1, citric acid helps to increase the relative content of tetrahedral Mo 6+ species in catalysts.…”

“…Therefore, the first peak at the low temperature region is attributed to the partial reduction of octahedral Mo 6+ species from Mo 6+ to Mo 4+ and the reduction of small crystalline MoO 3 [21,22]. Meanwhile, the second peak at the high temperature region is assigned to the reduction of the tetrahedral Mo 6+ species [23,24], and the further reduction of MoO 2 from Mo 4+ to Mo 0 [17].…”

“…Our previous study [17] has reported the structure of MoO 3 /Al 2 O 3 catalysts and their catalytic performance for sulfur-resistant methanation reactions. In this work, the role of citric acid in MoO 3 /Al 2 O 3 catalyst was studied.…”

Integrated Desulfurization and Methanation Concepts for SNG Production

“…The increased activity of the Ce-modified system was attributed to suppression of SO 4 2species by Ce, which are supposed to have a negative impact on methanation activity [24]. A systematic study of the effect of Mo loading and calcination temperature of Mo/γ Al 2 O 3 on the catalyst activity was performed [31]. The influence of the catalyst support on the activity of Co-Mo SRM catalysts was studied, comparing pure Al 2 O 3 and Al 2 O 3 modified with Ce, zr, Ti, or Mg [32].…”