Preparation and process optimization of porous carbons using different carbon sources and activating agents are frequently and commonly reported in open literature. However, only scanty references are made on utilizat...Preparation and process optimization of porous carbons using different carbon sources and activating agents are frequently and commonly reported in open literature. However, only scanty references are made on utilization of petroleum coke for conversion to high surface area porous carbon using KOH as the activating agent. Hence, the present work attempts a process optimization exercise to prepare high surface area porous carbon from Petroleum coke using chemical activation (KOH) utilizing design of experiments. The effect of activation temperature, petroleum coke to KOH ratio (KPR) and activation duration were assessed on the surface area and yield of the porous carbon. The process optimization was performed covering experimental parameters in the range of 500?C - 800?C, 2 - 5 and 30 - 120 min. The optimal process conditions for maximizing the yield and BET surface area was identified to be an activation temperature of 639?C, KPR of 4.5 and activation duration of 43 min, having BET surface area 1765 m2/g and yield of 89.8%. However, an attempt to maximize only the BET surface area, ignoring yield has resulted with a porous carbon with maximum surface area of 2061 m2/g, with the optimal process conditions being an activation temperature of 688?C, KPR of 3.8 and activation duration of 74 min, with the corresponding yield of only 77%. The characterization of porous carbon was performed using nitrogen adsorption isotherm, FT-IR and SEM analysis.展开更多
Cerium incorporated KIT-6 mesoporous materials were synthesized through direct hydrothermal method and characterized by using X-ray diffraction （XRD）, nitrogen sorption isotherm （BET）, Fourier transform infrared s...Cerium incorporated KIT-6 mesoporous materials were synthesized through direct hydrothermal method and characterized by using X-ray diffraction （XRD）, nitrogen sorption isotherm （BET）, Fourier transform infrared spectroscopy （FT-IR）, inductively coupled plasma - atomic emission spectroscopy （ICP-AES）, diffuse reflectance ultraviolet visible spectroscopy （DRS-UV-Vis）, ther- mogravimetric analysis （TGA）, scanning electron microscopy （SEM） and transmission electron microscopy （TEM） methods. It ap- peared that stable cerium ions were inserted into the silica framework of KIT-6, thus generating acid properties in their host materials. The catalytic activity of Ce-KIT-6 materials was evaluated in the vapor phase dehydration of cyclohexanol to cyclohexene and dicy- clohexyl ether at different temperatures with various Si/Ce molar ratios. Ce-KIT-6 （25） showed higher activity with 54% cyclohexa- nol conversion and 64% selectivity to cyclohexene. The catalytic results indicated that Ce-KIT-6 mesoporous materials could be used as versatile and stable acid catalysts.展开更多
文摘Preparation and process optimization of porous carbons using different carbon sources and activating agents are frequently and commonly reported in open literature. However, only scanty references are made on utilization of petroleum coke for conversion to high surface area porous carbon using KOH as the activating agent. Hence, the present work attempts a process optimization exercise to prepare high surface area porous carbon from Petroleum coke using chemical activation (KOH) utilizing design of experiments. The effect of activation temperature, petroleum coke to KOH ratio (KPR) and activation duration were assessed on the surface area and yield of the porous carbon. The process optimization was performed covering experimental parameters in the range of 500?C - 800?C, 2 - 5 and 30 - 120 min. The optimal process conditions for maximizing the yield and BET surface area was identified to be an activation temperature of 639?C, KPR of 4.5 and activation duration of 43 min, having BET surface area 1765 m2/g and yield of 89.8%. However, an attempt to maximize only the BET surface area, ignoring yield has resulted with a porous carbon with maximum surface area of 2061 m2/g, with the optimal process conditions being an activation temperature of 688?C, KPR of 3.8 and activation duration of 74 min, with the corresponding yield of only 77%. The characterization of porous carbon was performed using nitrogen adsorption isotherm, FT-IR and SEM analysis.
文摘Cerium incorporated KIT-6 mesoporous materials were synthesized through direct hydrothermal method and characterized by using X-ray diffraction （XRD）, nitrogen sorption isotherm （BET）, Fourier transform infrared spectroscopy （FT-IR）, inductively coupled plasma - atomic emission spectroscopy （ICP-AES）, diffuse reflectance ultraviolet visible spectroscopy （DRS-UV-Vis）, ther- mogravimetric analysis （TGA）, scanning electron microscopy （SEM） and transmission electron microscopy （TEM） methods. It ap- peared that stable cerium ions were inserted into the silica framework of KIT-6, thus generating acid properties in their host materials. The catalytic activity of Ce-KIT-6 materials was evaluated in the vapor phase dehydration of cyclohexanol to cyclohexene and dicy- clohexyl ether at different temperatures with various Si/Ce molar ratios. Ce-KIT-6 （25） showed higher activity with 54% cyclohexa- nol conversion and 64% selectivity to cyclohexene. The catalytic results indicated that Ce-KIT-6 mesoporous materials could be used as versatile and stable acid catalysts.
