Synthesis and Characterization of Cobalt/Manganese Bimetallic Nanocatalyst Prepared via Reverse Microemulsion Method

• Main Author: A. Rahman, Mohamad Suffian
• Format: Final Year Project
• Language: English
• Published: Universiti Teknologi PETRONAS 2013
• Subjects: TP Chemical technology
• Online Access: http://utpedia.utp.edu.my/8469/1/MOHAMAD%20SUFFIAN%20B.%20A.%20RAHMAN%20%2812659%29%20CHEMICAL%20ENGINEERING.pdf; http://utpedia.utp.edu.my/8469/

The bimetallic cobalt-manganese nanocatalyst was synthesized via reverse microemulsion method. The reverse microemulsion was used as an alternative route to prepare the nanocatalyst rather than common catalyst preparation route, impregnation method as the later have reported problem with the metal dispersion. In this project, the main objective is to synthesize well-dispersed bimetallic nanocatalyst consisting of cobalt-manganese in different composition on silica support via reverse microemulsion method, to study the properties of catalyst by applying several characterization methods and to study the catalytic performance in a Fischer-Tropsch (FT) reaction. The following compositions were prepared which are pure cobalt, pure manganese, 95Co5Mn/SiO2, 88Co12Mn/SiO2 and 76Co24Mn/SiO2. The nanocatalyst was analyzed by using Transmission Electron Microscopy (TEM), Field Emission Scanning Electron Microscopy (FESEM) and Temperature Programmed Reduction (TPR). The performance of the nanocatalyst for FT reaction was studied in a stainless steel fixed bed micro reactor. The average particle size of the nanocatalyst was 2-5 nm. TEM image show nanocatalyst 88Co12Mn/SiO2 was better dispersed compared to other formulations. The TPR result of the 100Co/SiO2 and 95Co5Mn/SiO2 showed that these nanocatalysts were reduced at the temperatures of 690 oC and 645 oC, respectively. The reducibility was improved when 12 wt% Mn was added to Co-based nanocatalyst for 88Co12Mn/SiO2 since the high temperature peak was shifted to lower temperature (536 oC). However, further increase in Mn content (24 wt%) had shifted the high temperature peak to higher temperature (600 oC). This indicates that the optimum Mn content (12 wt%) enhanced the reducibility of the Co-based nanocatalyst. The catalytic activity in the FT reaction varied with the content of Mn in the Co-based nanocatalyst. In conclusion, the highest CO conversion (20.5%) and C5+ selectivity (12.6%) were obtained using 88Co12Mn/SiO2 nanocatalyst.