Optimisation of synthesis parameters for Co-Mo/MgO catalyst yield in MWCNTs production

Abstract

This study examined the impact of synthesis parameter on Cobalt-Molybdenum supported with magnesium oxide (Co-Mo/MgO) catalyst yield in production of multiwall carbon nanotube (MWCNT). Wet impregnation was used to synthesis the Co-Mo/MgO bimetallic catalyst, while a catalytic chemical vapour deposition reactor (CCVD) was used for the synthesis of carbon nanotubes (CNTs). Factorial and central composite design techniques were used to optimise the catalyst and multi-wall carbon nanotubes (MWCNTs). Thermogravimetric analysis/ Differential thermal analysis (TGA/DTA), selected area (electron) diffraction (SAED), X-Ray diffraction analysis (XRD), and Brunauer–Emmett–Teller (BET) were used to characterise the catalyst and MWCNTs that were produced. The Co-Mo/MgO catalyst had an optimal yield of 93.22%, 247.30 m2/g of specific surface area at 120 °C drying temperature, 16 g of mass support, and a 10-hour drying time. The maximum catalyst yield of 40.62% was obtained at calcination temperature of 500 °C and a holding period of 2 hours. The catalyst with the highest degradation temperature of 398.21 °C was observed at 600 °C, when calcined for 4 hours. It was discovered that the surface area of Co-Mo/MgO catalyst from the BET analysis under ideal conditions varied depending on the holding time. The XRD and SAED revealed the growth of CNTs of concentric graphene pattern with the Co-Mo/MgO catalyst.