3.2 Effects of particle size
The particle size of the catalyst was highly influenced on the reaction rate, when the particle size of the catalyst was decreased, therefore their surface areas was increased and the ratio of catalyst surface and reactant volume was playing a crucial role for controlling the reaction kinetics. The reaction was takes place on the surface of a substance, increasing the surface area should increases the quantity of the substance that is available to react, and will thus increase the rate of the reaction as well. The size and shape of the CuMnOx catalyst particles was a transaction between the minimize pore diffusion effects in the catalyst particles. The particle size provides information about the reaction behavior …show more content…
The catalytic activity for the oxidation of CO was investigated for the range of materials and the activity with respect to time on line. The drying time of CuMnOx catalyst was also influence on the performance of the resultant catalyst activity. The drying time effect on the catalyst activity was shown in fig. 4. The catalytic activity was increases with the increasing of the drying time up to 12 hr of the precursor at a fixed temperature 110oC temperature with further increasing the drying time the activity of the catalyst was decreased. This results shows that drying the precipitate under these conditions for 12 hr gives the highest CO conversion. During the drying period of the solution retained by the porous support may migrate by capillary flow and diffusion and the solute redistributed by desorption and re-adsorption. When the solvent evaporates, precipitation of solute happens as the solution becomes supersaturated and brings crystallization of the precursors in the pores and outer surface of the …show more content…
The calcination temperature of the catalyst was followed between the (200oC-400oC) in a flowing air calcination conditions. The percentage of CO oxidation was shown in the figure 4. With the increasing calcination temperature of the precursor, the catalytic activity was increases and it could be observed before reached to 300oC temperature. Fig. 4. The optimization in calcination temperature of CuMnOx (CuMn8) precursor
The optimum calcination temperature of the CuMnOx catalyst was 300oC and further increasing the calcination temperature the activity of the catalyst was decreases. There was a correlation between the surface area and the calcination temperature of the catalyst. When the calcination temperature of the CuMnOx catalyst was increased above 300oC, the surface area was decreases and its analysis by BET measurement. The crystallinity was also increased as the increasing of the calcination temperature of the precursor, therefore the diffraction peaks at the XRD analysis was more crystalline phases produced by calcination at (200 - 400oC) temperature. The catalyst calcined at 300oC for 2hr showed the best catalytic activity for complete oxidation of CO at 120oC temperature. The increases calcination temperature resulting increases the oxidation
The particle size of the catalyst was highly influenced on the reaction rate, when the particle size of the catalyst was decreased, therefore their surface areas was increased and the ratio of catalyst surface and reactant volume was playing a crucial role for controlling the reaction kinetics. The reaction was takes place on the surface of a substance, increasing the surface area should increases the quantity of the substance that is available to react, and will thus increase the rate of the reaction as well. The size and shape of the CuMnOx catalyst particles was a transaction between the minimize pore diffusion effects in the catalyst particles. The particle size provides information about the reaction behavior …show more content…
The catalytic activity for the oxidation of CO was investigated for the range of materials and the activity with respect to time on line. The drying time of CuMnOx catalyst was also influence on the performance of the resultant catalyst activity. The drying time effect on the catalyst activity was shown in fig. 4. The catalytic activity was increases with the increasing of the drying time up to 12 hr of the precursor at a fixed temperature 110oC temperature with further increasing the drying time the activity of the catalyst was decreased. This results shows that drying the precipitate under these conditions for 12 hr gives the highest CO conversion. During the drying period of the solution retained by the porous support may migrate by capillary flow and diffusion and the solute redistributed by desorption and re-adsorption. When the solvent evaporates, precipitation of solute happens as the solution becomes supersaturated and brings crystallization of the precursors in the pores and outer surface of the …show more content…
The calcination temperature of the catalyst was followed between the (200oC-400oC) in a flowing air calcination conditions. The percentage of CO oxidation was shown in the figure 4. With the increasing calcination temperature of the precursor, the catalytic activity was increases and it could be observed before reached to 300oC temperature. Fig. 4. The optimization in calcination temperature of CuMnOx (CuMn8) precursor
The optimum calcination temperature of the CuMnOx catalyst was 300oC and further increasing the calcination temperature the activity of the catalyst was decreases. There was a correlation between the surface area and the calcination temperature of the catalyst. When the calcination temperature of the CuMnOx catalyst was increased above 300oC, the surface area was decreases and its analysis by BET measurement. The crystallinity was also increased as the increasing of the calcination temperature of the precursor, therefore the diffraction peaks at the XRD analysis was more crystalline phases produced by calcination at (200 - 400oC) temperature. The catalyst calcined at 300oC for 2hr showed the best catalytic activity for complete oxidation of CO at 120oC temperature. The increases calcination temperature resulting increases the oxidation