A First-Principles Study of Oxygenates on Co Surfaces in Fischer−Tropsch Synthesis

• DOI: 10.1021/jp802242t
• Publication Date: 2008-06-04T07:00:56Z
• Authors: Jun Cheng; P. Hu; Peter Ellis; Sam French; Gordon Kelly; C. Martin Lok
• Keywords: Oxygenate; Fischer–Tropsch process

Extensive density function theory calculations are performed to study the mechanism of formation aldehyde and alcohol on Co surfaces in Fischer−Tropsch synthesis, a challenging issue heterogeneous catalysis. Three possible pathways for production formaldehyde methanol flat stepped Co(0001) investigated: (i) CO + 4H → CHO 3H CH2O 2H CH3O H CH3OH; (ii) COH CHOH CH2OH (iii) coupling reactions CH2 O CH3 OH CH3OH. It is found that these generally favored at step sites, preferred pathway via CHO. Furthermore, three traditional chain growth mechanisms synthesis semiquantitatively compared discussed. Our results suggest two involving oxygenate intermediates (the CO-insertion hydroxycarbene mechanisms) less important than carbene long hydrocarbons. However, may be responsible long-chain oxygenates.