Effect of pH, Acid and Thermal Treatment Conditions on Co/CNT Catalyst Performance in Fischer–Tropsch Reaction

• Main Authors: Akbarzadeh, Omid, Mohd Zabidi, Noor Asmawati, Hamizi, Nor Aliya, Wahab, Yasmin Abdul, Merican, Zulkifli Merican Aljunid, Yehya, Wageeh Abdulhadi, Akhter, Shamima, Shalauddin, Md, Rasouli, Elisa, Johan, Mohd Rafie
• Format: Article
• Published: MDPI 2019
• Subjects: QD Chemistry
• Online Access: http://eprints.um.edu.my/24378/; https://doi.org/10.3390/sym11010050

Multiwalled carbon nanotubes (CNT) supported cobalt oxide was prepared as a catalyst by strong electrostatic adsorption (SEA) method. The CNT support was initially acid- and thermal-treated in order to functionalize the support to uptake more Co clusters. The Co/CNT were characterized by a range of analytical methods including transmission electron microscopy (TEM), temperature programmed reduction with hydrogen (H2-TPR), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, atomic absorption spectroscopy (AAS), Zeta sizer particle size analysis and Brunauer-Emmett-Teller (BET) surface area analysis. TEM images showed cobalt particles were highly dispersed and impregnated at both exterior and interior walls of the CNT support with a narrow particle size distribution of 6-8 nm. In addition, the performance of the synthesized Co/CNT catalyst was tested using Fischer-Tropsch synthesis (FTS) reaction which was carried out in a fixed-bed micro-reactor. H2-TPR profiles indicated the lower reduction temperature of 420 °C was required for the FTS reaction. The study revealed that cobalt is an effective metal for Co/CNT catalysts at pH 14 and at 900 °C calcination temperature. Furthermore, FTS reaction results showed that CO conversion and C5+ selectivity were recorded at 58.7% and 83.2% respectively, which were higher than those obtained using a Co/CNT catalyst which pre-treated at a lower thermal treatment temperature and pH. © 2019 by the authors.