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Hydroprocessing of Maya vacuum residue using a NiMo catalyst supported on Cr-doped alumina

“…In the literature, for Mo 0 , Mo 4+ , Mo 5+ , and Mo 6+ , the Mo3d Ni reductions to the point of nearly eliminating the shoulder between them. This indicates a better reducibility in the presence of Cr, as had been reported for Ni [18] and Mo, the latter being easier to reduce with increasing Cr content in doped γ-alumina [68]. In catalysts supported on mesoporous silica, Cr presented a reduction peak at 420 °C, Mo at 522 °C and the CrMo catalyst had a peak which combined the two reductions at a temperature in the centre of the monometallic catalysts (ca.…”

Oxydehydrogenation of Ethane and Propane over Alkaline Metal Modified Fe-ZSM-5 Zeolites

“…This means that propane is transformed first to propene and subsequently propene undergoes further reactions. According to literature data [50,51] propene formed as a product of ODH reaction may undergo dimerization in the presence of medium and weak acidic centres both of the Lewis and Brønsted type and further transformation to short hydrocarbons. An amount of C 2 hydrocarbons as a result of propane ODH reaction and consecutive propene transformation was noted over lithium modified MoO 3 / Al 2 O 3 catalyst [51], characterised by low acidity.…”

The Role of CO2 as a Mild Oxidant in Oxidation and Dehydrogenation over Catalysts: A Review

“…Thus, extracting the aluminum from HZSM-5 declines the Bronsted acidity more than it decreases the Lewis acidity. Several transition metals, such as vanadium, molybdenum, and chromium, have been used to support catalysts for ODH of light alkanes including propane [105,112,119,120]. Among these, chromium oxide provided high catalytic performance with CO 2 , despite fractional deactivation by coke production.…”