Promoting effect of CeO2, ZrO2 and Ce/Zr mixed oxides on Co/Γ-Al2O3 catalyst for Fischer-Tropsch synthesis

• A series of cobalt-based catalysts have been synthesized using as support γ-Al2O3 promoted by ceria/zirconia mixed oxides with a variable Ce/Zr molar ratio. The obtained catalysts demonstrated oxide promotion results in the protection of the major textural properties, especially for Zr-rich solids. Reducibility of cobalt species was enhanced by the presence of mixed oxides. The chemical composition of the oxide promoter influenced not only physicochemical properties of final catalysts but also determined their performance during the reaction. In this sense, Zr-rich systems presented a superior catalytic performance both in total conversion and in selectivity towards long chain hydrocarbons. The observed Zr-promotion effect could be explained by two significant contributions: firstly, the partial inhibition of Co–Al spinel compound formation by the presence of Zr-rich phases which enhances the availability of Co actives site and secondly, Zr-associate acidic sites promote higher hydrocarbons selectivity.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Kemiteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Chemical Engineering (hsv//eng)

Nyckelord

Cobalt-based catalysts

GTL

Higher hydrocarbon selectivity

Oxide promoter

Support acidity

Zr–Ce oxides

Alumina

Aluminum oxide

Catalyst activity

Catalyst selectivity

Cobalt

Cobalt compounds

Fischer-Tropsch synthesis

Hydrocarbons

Zirconia

Catalytic performance

Chemical compositions

Higher hydrocarbons

Long chain hydrocarbons

Physicochemical property

Promotion effects

Textural properties

Cerium oxide

acidity

aluminum

catalyst

cerium

chemical composition

chemical reaction

hydrocarbon

oxide

zircon

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)