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Discover Chemical Engineering
Active areas of research on chemical looping technologies for the conversion of CO2 to CO are con... more Active areas of research on chemical looping technologies for the conversion of CO2 to CO are contrasted and discussed, including current performance, methods for material design, and next steps in expanding their development. Generation of CO from CO2 is of interest in sustainable chemistry and engineering to convert anthropogenic CO2 emissions into feedstock for Fischer–Tropsch (FT), methanol to gasoline (MTG), gas-to-liquid (GTL), and other synthesis pathways for fuels and materials. Chemical looping strategies have been identified which not only produce CO, but also H2 from H2O and methane sources, supplying the other key component of syngas. Configurations of these chemical looping technologies into the materials economy potentially constitute sustainable carbon loop cycles for fuels as well as carbon sequestration into industrial and commercial materials. Major areas of research in CO2 conversion by chemical looping, collectively referred to here as CO2CL, including Solar-Ther...
Journal of Industrial and Engineering Chemistry
As the greenhouse gas effect becomes more serious, it is important to find an effective way to re... more As the greenhouse gas effect becomes more serious, it is important to find an effective way to reduce carbon dioxide emissions and/or convert it to value-added products. Based on the catalytic requirements, convert CO2 to CO using perovskite-type oxides which are suitable for reverse water-gas shift chemical looping (RWGS-CL). The resulting carbon monoxide can be subsequently used for chemical energy storage in the form of hydrocarbon-based fuels and chemicals. This research focuses on the synthesis of the LaxBa1-xFeyAl1-yO3 perovskite-type oxides, which can form oxygen vacancies, or active sites for CO2 conversion. Multiple measurement methods were using for testing synthesized catalysts. Temperature-programmed reduction (TPR) and temperature-programmed oxidation (TPO) experiments were performed to identify reaction temperatures and redox properties of the materials. Surface areas were measured, and X-ray diffraction was utilized to identify the crystal structure. La0.25Ba0.75FeO3 ...
As the greenhouse gas effect becomes more serious, it is important to find an effective way to re... more As the greenhouse gas effect becomes more serious, it is important to find an effective way to reduce carbon dioxide emissions and/or convert it to value-added products. Based on the catalytic requirements, convert CO2 to CO using perovskite-type oxides which are suitable for reverse water-gas shift chemical looping (RWGS-CL). The resulting carbon monoxide can be subsequently used for chemical energy storage in the form of hydrocarbon-based fuels and chemicals. This research focuses on the synthesis of the LaxBa1-xFeyAl1-yO3 perovskite-type oxides, which can form oxygen vacancies, or active sites for CO2 conversion. Multiple measurement methods were using for testing synthesized catalysts. Temperature-programmed reduction (TPR) and temperature-programmed oxidation (TPO) experiments were performed to identify reaction temperatures and redox properties of the materials. Surface areas were measured, and X-ray diffraction was utilized to identify the crystal structure. La0.25Ba0.75FeO3 ...
A helical-shaped metal-organic framework was prepared using conformationally rigid tetratopic ben... more A helical-shaped metal-organic framework was prepared using conformationally rigid tetratopic benzoic acid ligand with binding units pointing toward each other (concave ligand). To avoid the obvious intramolecular interactions between binding units, matching spacing groups was applied to introduce atropic repulsion, allowing the formation of extended frameworks for the first time. With this new ligand design, a helical-shaped MOF was successfully prepared with significantly improved air and moisture stability, providing a new strategy for ligand design toward porous material constructions.
Journal of CO2 Utilization, 2021
Abstract Reverse water-gas shift chemical looping (RWGS-CL) is a low temperature thermochemical p... more Abstract Reverse water-gas shift chemical looping (RWGS-CL) is a low temperature thermochemical process to convert CO2 to CO by perovskite oxides. In this research, perovskite oxides of the form of La1-xBaxFeO3 (x = 0.25−0.75) are explored for enhancing CO yield while maintaining stability over multiple cycles. DFT was utilized to calculate the oxygen vacancy formation energies (Evac) identifying Evac of La0.75Ba0.25FeO3 (3.3 eV) and La0.5Ba0.5FeO3 (3.0 eV) are in the ideal range of 3.4 ± 0.5 eV. Additional Ba resulted in instability. XRD confirmed cubic perovskite structure and XRF analysis established the precise composition. XPS revealed that the materials had Ba enrichment at the surface, compared to the overall bulk. Temperature-programmed reduction (TPR) and oxidation (TPO) experiments determined that CO2 is converted to CO in the low temperature range of 400–600 °C for all compositions, which is lower than temperatures of many thermochemical CO2 processes. Isothermal cycling between hydrogen and CO2 at 600 °C indicated La0.5Ba0.5FeO3 and La0.4Ba0.6FeO3 were stable (verified by XRD and XPS) and produced CO at high yields of 200 and 500 μmol/gLBF, respectively. The CO2 conversion step fits to Langmuir–Hinshelwood type kinetics based on its partial pressure dependency and is consistent with DRIFTS studies. Therefore, multiple materials in this study enhance performance, indicating their suitability for industrial scale adaptation upon energy integration as a possible strategy for renewable energy storage in chemical form.
Discover Chemical Engineering
Active areas of research on chemical looping technologies for the conversion of CO2 to CO are con... more Active areas of research on chemical looping technologies for the conversion of CO2 to CO are contrasted and discussed, including current performance, methods for material design, and next steps in expanding their development. Generation of CO from CO2 is of interest in sustainable chemistry and engineering to convert anthropogenic CO2 emissions into feedstock for Fischer–Tropsch (FT), methanol to gasoline (MTG), gas-to-liquid (GTL), and other synthesis pathways for fuels and materials. Chemical looping strategies have been identified which not only produce CO, but also H2 from H2O and methane sources, supplying the other key component of syngas. Configurations of these chemical looping technologies into the materials economy potentially constitute sustainable carbon loop cycles for fuels as well as carbon sequestration into industrial and commercial materials. Major areas of research in CO2 conversion by chemical looping, collectively referred to here as CO2CL, including Solar-Ther...
Journal of Industrial and Engineering Chemistry
As the greenhouse gas effect becomes more serious, it is important to find an effective way to re... more As the greenhouse gas effect becomes more serious, it is important to find an effective way to reduce carbon dioxide emissions and/or convert it to value-added products. Based on the catalytic requirements, convert CO2 to CO using perovskite-type oxides which are suitable for reverse water-gas shift chemical looping (RWGS-CL). The resulting carbon monoxide can be subsequently used for chemical energy storage in the form of hydrocarbon-based fuels and chemicals. This research focuses on the synthesis of the LaxBa1-xFeyAl1-yO3 perovskite-type oxides, which can form oxygen vacancies, or active sites for CO2 conversion. Multiple measurement methods were using for testing synthesized catalysts. Temperature-programmed reduction (TPR) and temperature-programmed oxidation (TPO) experiments were performed to identify reaction temperatures and redox properties of the materials. Surface areas were measured, and X-ray diffraction was utilized to identify the crystal structure. La0.25Ba0.75FeO3 ...
As the greenhouse gas effect becomes more serious, it is important to find an effective way to re... more As the greenhouse gas effect becomes more serious, it is important to find an effective way to reduce carbon dioxide emissions and/or convert it to value-added products. Based on the catalytic requirements, convert CO2 to CO using perovskite-type oxides which are suitable for reverse water-gas shift chemical looping (RWGS-CL). The resulting carbon monoxide can be subsequently used for chemical energy storage in the form of hydrocarbon-based fuels and chemicals. This research focuses on the synthesis of the LaxBa1-xFeyAl1-yO3 perovskite-type oxides, which can form oxygen vacancies, or active sites for CO2 conversion. Multiple measurement methods were using for testing synthesized catalysts. Temperature-programmed reduction (TPR) and temperature-programmed oxidation (TPO) experiments were performed to identify reaction temperatures and redox properties of the materials. Surface areas were measured, and X-ray diffraction was utilized to identify the crystal structure. La0.25Ba0.75FeO3 ...
A helical-shaped metal-organic framework was prepared using conformationally rigid tetratopic ben... more A helical-shaped metal-organic framework was prepared using conformationally rigid tetratopic benzoic acid ligand with binding units pointing toward each other (concave ligand). To avoid the obvious intramolecular interactions between binding units, matching spacing groups was applied to introduce atropic repulsion, allowing the formation of extended frameworks for the first time. With this new ligand design, a helical-shaped MOF was successfully prepared with significantly improved air and moisture stability, providing a new strategy for ligand design toward porous material constructions.
Journal of CO2 Utilization, 2021
Abstract Reverse water-gas shift chemical looping (RWGS-CL) is a low temperature thermochemical p... more Abstract Reverse water-gas shift chemical looping (RWGS-CL) is a low temperature thermochemical process to convert CO2 to CO by perovskite oxides. In this research, perovskite oxides of the form of La1-xBaxFeO3 (x = 0.25−0.75) are explored for enhancing CO yield while maintaining stability over multiple cycles. DFT was utilized to calculate the oxygen vacancy formation energies (Evac) identifying Evac of La0.75Ba0.25FeO3 (3.3 eV) and La0.5Ba0.5FeO3 (3.0 eV) are in the ideal range of 3.4 ± 0.5 eV. Additional Ba resulted in instability. XRD confirmed cubic perovskite structure and XRF analysis established the precise composition. XPS revealed that the materials had Ba enrichment at the surface, compared to the overall bulk. Temperature-programmed reduction (TPR) and oxidation (TPO) experiments determined that CO2 is converted to CO in the low temperature range of 400–600 °C for all compositions, which is lower than temperatures of many thermochemical CO2 processes. Isothermal cycling between hydrogen and CO2 at 600 °C indicated La0.5Ba0.5FeO3 and La0.4Ba0.6FeO3 were stable (verified by XRD and XPS) and produced CO at high yields of 200 and 500 μmol/gLBF, respectively. The CO2 conversion step fits to Langmuir–Hinshelwood type kinetics based on its partial pressure dependency and is consistent with DRIFTS studies. Therefore, multiple materials in this study enhance performance, indicating their suitability for industrial scale adaptation upon energy integration as a possible strategy for renewable energy storage in chemical form.