Cobalt Oxide on N‑Doped Carbon for 1‑Butene Oligomerization to Produce Linear Octenes

• Published in: ACS catalysis 2017-11, Vol.7 (11), p.7479-7489
• Main Authors: Zhao, Dongting, Xu, Zhuoran, Chada, Joseph P, Carrero, Carlos A, Rosenfeld, Devon C, Rogers, Jessica L, Hermans, Ive, Huber, George W
• Format: Article
• Language: English
• Subjects: heterogeneous catalysis; INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; linear olefin; metal oxide catalyst; nitrogen-doped carbon; oligomerization
• ISSN: 2155-5435; 2155-5435
• DOI: 10.1021/acscatal.7b01482

Cobalt oxide supported on N-doped carbon catalysts were investigated for 1-butene oligomerization. The materials were synthesized by treating activated carbon with nitric acid and subsequently with NH3 at 200, 400, 600, and 800 °C, followed by impregnation with cobalt. The 1-butene oligomerization selectivity increased with ammonia treatment temperature of the carbon support. The oligomerization selectivity of cobalt oxide on N-doped carbon synthesized at 800 °C (800A-CoOx/N-C) is 2.6 times higher than previously reported cobalt oxide on N-doped carbon synthesized with NH4OH (2A-CoOx/N-C). Over 70% of the butene dimers were linear C8 olefins for all catalysts. The oligomerization selectivity increased with 1-butene conversion. The catalysts were characterized by elemental analysis, N2 adsorption, X-ray diffraction (XRD), X-ray absorption spectroscopy (XAS), and X-ray photoelectron spectroscopy (XPS). The nitrogen content of the catalysts increases with ammonia treatment temperature as confirmed by elemental analysis. The surface content of pyridinic nitrogen with a binding energy of 398.4 ± 0.1 eV increased with ammonia treatment temperature as evidenced by deconvolution of N 1s XPS spectra.