Syngas to Chemicals: The Incorporation of Aldehydes into Fischer-Tropsch Synthesis

Syngas is an important intermediate for the synthesis of chemicals and fuels; it can be produced from renewable and fossil feedstocks. Syngas conversion on Fe catalysts results mostly in linear paraffins, olefins, and oxygenates. In the produced olefins or oxygenates, the functional groups or double bonds are always located in the hydrocarbon alpha-position. The yield of nonlinear functionalized hydrocarbons or chemical compounds with secondary and tertiary functional groups is low. In this paper direct synthesis of diverse functionalized and branched hydrocarbons in the Fischer-Tropsch reaction is explored by the cofeeding aldehydes to syngas; the added aldehydes initiate surface polymerization. Quantitative stoichiometric incorporation of aldehydes in the growing hydrocarbon chain was observed. The hydrocarbons that contain incorporated aldehyde fragments exhibit an Anderson-Schulz-Flory distribution similar to that from conventional Fischer-Tropsch synthesis.