Chinese Journal of Catalysis ›› 2019, Vol. 40 ›› Issue (11): 1731-1740.DOI: 10.1016/S1872-2067(19)63344-9

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On the role of cobalt carbidization in higher alcohol synthesis over hydrotalcite-based Co-Cu catalysts

Janine Nebela, Stefan Schmidta, Qiushi Pana, Katrin Lotza, Stefan Kaluzaa,b, Martin Muhlera   

  1. a Laboratory of Industrial Chemistry, Ruhr-University Bochum, Universitätsstr. 150, 44780 Bochum, Germany;
    b Fraunhofer Institute for Environmental, Safety, and Energy Technology UMSICHT, Osterfelder Str. 3, 46047 Oberhausen, Germany
  • Received:2019-01-25 Revised:2019-03-07 Online:2019-11-18 Published:2019-09-06
  • Contact: Stefan Kaluza, Martin Muhler
  • Supported by:
    The research project is funded by the Federal Ministry of Education and Research (Bundesministerium für Bildung und Forschung, BMBF, Ver-bundvorhaben Carbon2Chem®, FKZ:03EK3041).

Abstract: Co-Cu-based catalysts are widely applied in higher alcohol synthesis (HAS) from synthesis gas. Although the nature of the active sites is still not fully understood, the formation of Co2C under HAS conditions seems to play a major role. A CO pretreatment procedure was developed allowing a systematic investigation of the influence of cobalt carbidization on the structural properties and catalytic performance of the catalysts. By exposing the catalyst to a CO-containing atmosphere prior to HAS, Co enrichment of the catalyst surface occurred followed by carbide formation. This surface modification decreased the formation of hydrocarbons and enhanced the formation of C2+OH. The catalyst pretreated with CO at 20 bar achieved the highest selectivity to ethanol and the lowest hydrocarbon selectivity.

Key words: Higher alcohol synthesis, Co-Cu catalyst, Co2C, CO pretreatment