The Experts below are selected from a list of 294 Experts worldwide ranked by ideXlab platform
Masahiro Saito - One of the best experts on this subject based on the ideXlab platform.
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Development of high performance Cu/ZnO-based catalysts for methanol synthesis and the water-gas Shift Reaction
Catalysis Surveys from Asia, 2004Co-Authors: Masahiro Saito, Kazuhisa MurataAbstract:Our group’s studies on Cu/ZnO-based catalysts for methanol synthesis via hydrogenation of CO2 and for the water-gas Shift Reaction are reviewed. Effects of ZnO contained in supported Cu-based catalysts on their activities for several Reactions were investigated. The addition of ZnO to Cu-based catalyst supported on Al2O3, ZrO2 or SiO2 improved its specific activity for methanol synthesis and the reverse water-gas Shift Reaction, but did not improve its specific activity for methanol steam reforming and the water-gas Shift Reaction. Methanol synthesis from CO2 and H2 over Cu/ZnO-based catalysts was extensively studied under a joint research project between National Institute for Resources and Environment (NIRE; one of the former research institutes reorganized to AIST) and Research Institute of Innovative Technology for the Earth (RITE). It was suggested that methanol should be produced via the hydrogenation of CO2, but not via the hydrogenation of CO, and that H2O produced along with methanol should greatly suppress methanol synthesis. The Cu/ZnO-based multicomponent catalysts such as Cu/ZnO/ZrO2/Al2O3 and Cu/ZnO/ZrO2/Al2O3/Ga2O3 were highly active for methanol synthesis from CO2 and H2. The addition of a small amount of colloidal silica to the multicomponent catalysts greatly improved their long-term stability during methanol synthesis from CO2 and H2. The purity of the crude methanol produced in a bench plant was 99.9 wt% and higher than that of the crude methanol from a commercial methanol synthesis from syngas. The water-gas Shift Reaction over Cu/ZnO-based catalysts was also studied. The activity of Cu/ZnO/ZrO2/Al2O3 catalyst for the water-gas Shift Reaction at 523 K was less affected by the pre-treatments such as calcination and treatment in H2 at high temperatures than that of the Cu/ZnO/Al2O3 catalyst. Accordingly, the Cu/ZnO/ZrO2/Al2O3 catalyst was considered to be more suitable for practical use for the water-gas Shift Reaction. The Cu/ZnO/ZrO2/Al2O3 catalyst was also highly active for the water-gas Shift Reaction at 673 K. Furthermore, a two-stage Reaction system composed of the first Reaction zone for the water-gas Shift Reaction at 673 K and the second Reaction zone for the Reaction at 523 K was found to be more efficient than a one-stage Reaction system. The addition of a small amount of colloidal silica to a Cu/ZnO-based catalyst greatly improved its long-term stability in the water-gas Shift Reaction in a similar manner as in methanol synthesis from CO2 and H2.
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Effects of Pretreatments of Cu/ZnO-Based Catalysts on Their Activities for the Water–Gas Shift Reaction
Catalysis Letters, 2003Co-Authors: Masahiro Saito, Kazuhisa Murata, Kazumi Tomoda, Isao Takahara, Megumu InabaAbstract:The effects of the pretreatments of Cu/ZnO-based catalysts prepared by a coprecipitation method on their activities for the water–gas Shift Reaction at 523K were investigated. The activity of a Cu/ZnO/ZrO2/Al2O3 catalyst for the water–gas Shift Reaction was less affected by calcination at temperatures ranging from 673-973K and by H2 treatment at 573 or 723K than that of a Cu/ZnO/Al2O3 catalyst. The catalyst activity could be correlated mainly to the Cu surface area of the catalyst.
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Improvement of stability of a Cu/ZnO/Al2O3 catalyst for the CO Shift Reaction
Journal of Catalysis, 2000Co-Authors: Masahiro SaitoAbstract:The stability of a Cu/ZnO/Al2O3 catalyst in the CO Shift Reaction was improved by the addition of a small amount of silica into the catalyst, probably due to the suppression of the crystallization of the metal oxides contained in the catalyst, especially ZnO, which could be caused by the steam in the feed during the Reaction.
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Reverse Water-Gas Shift Reaction Catalyzed by Ruthenium Cluster Anions.
Chemistry Letters, 1994Co-Authors: Ken-ichi Tominaga, Yoshiyuki Sasaki, Kohnosuke Hagihara, Taiki Watanabe, Masahiro SaitoAbstract:Reverse water-gas Shift Reaction (H2 + CO2 → CO + H2O) was homogeneously catalyzed by anionic Ru cluster in the presence of bis(triphenylphosphine)imminium chloride ([PPN]Cl). The catalytic Reaction was estimated to proceed via dehydrogenation of hydride cluster, followed by coordination of CO2 and electrophilic attack of proton on its oxygen atom in the presence of chloride anion.
Sung-hwan Han - One of the best experts on this subject based on the ideXlab platform.
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development of zno al2o3 catalyst for reverse water gas Shift Reaction of camere carbon dioxide hydrogenation to form methanol via a reverse water gas Shift Reaction process
Applied Catalysis A-general, 2001Co-Authors: Sang Woo Park, Oh Shim Joo, Kwang-deog Jung, Hyo Kim, Sung-hwan HanAbstract:Abstract ZnO and ZnO/Al2O3 catalysts were studied for a reverse-water-gas-Shift Reaction (RWReaction). The catalytic activities depended on the compositions of Zn and Al at the temperature range of 673–973 K and GHSV of 15,000. The activities were close to the equilibrium conversion at temperatures above 873 K. The catalysts were characterized by using BET, TPR, XRD, SEM, and TEM. The ZnO/Al2O3 catalysts were mixtures of ZnO and ZnAl2O4 phases, and the particle size of the ZnO was strongly dependent on its composition in the ZnO/Al2O3 catalysts. ZnO/Al2O3 (Zn:Al=1:1) catalyst has the smallest particle size of ZnO and its conversion of CO2 at 873 K and GHSV of 150,000 was 43%. The stability of ZnO/Al2O3 catalysts increased in the presence of the large particles of ZnO. Hence, ZnO/Al2O3 (Zn:Al=4:1) catalyst was more stable than the ZnO/Al2O3 (Zn:Al=1:1) catalyst. The conversion of CO2 on the ZnO/Al2O3 (Zn:Al=1:1) catalyst decreased from 43 to 17% in 48 h. The ZnO in ZnO/Al2O3 catalysts was reduced to the Zn metal during the RWReaction, which contributed to the deactivation of the ZnO/Al2O3 catalysts. Meanwhile, the activity of ZnAl2O4 catalyst was stable for 100 h at 873 K and GHSV of 150,000. The ZnAl2O4 catalyst was developed for the RWReaction of the CAMERE (carbon dioxide hydrogenation to form methanol via a reverse-water-gas-Shift Reaction) process for methanol formation from CO2.
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Development of ZnO/Al2O3 catalyst for reverse-water-gas-Shift Reaction of CAMERE (carbon dioxide hydrogenation to form methanol via a reverse-water-gas-Shift Reaction) process
Applied Catalysis A: General, 2001Co-Authors: Sang Woo Park, Oh Shim Joo, Kwang-deog Jung, Hyo Kim, Sung-hwan HanAbstract:Abstract ZnO and ZnO/Al2O3 catalysts were studied for a reverse-water-gas-Shift Reaction (RWReaction). The catalytic activities depended on the compositions of Zn and Al at the temperature range of 673–973 K and GHSV of 15,000. The activities were close to the equilibrium conversion at temperatures above 873 K. The catalysts were characterized by using BET, TPR, XRD, SEM, and TEM. The ZnO/Al2O3 catalysts were mixtures of ZnO and ZnAl2O4 phases, and the particle size of the ZnO was strongly dependent on its composition in the ZnO/Al2O3 catalysts. ZnO/Al2O3 (Zn:Al=1:1) catalyst has the smallest particle size of ZnO and its conversion of CO2 at 873 K and GHSV of 150,000 was 43%. The stability of ZnO/Al2O3 catalysts increased in the presence of the large particles of ZnO. Hence, ZnO/Al2O3 (Zn:Al=4:1) catalyst was more stable than the ZnO/Al2O3 (Zn:Al=1:1) catalyst. The conversion of CO2 on the ZnO/Al2O3 (Zn:Al=1:1) catalyst decreased from 43 to 17% in 48 h. The ZnO in ZnO/Al2O3 catalysts was reduced to the Zn metal during the RWReaction, which contributed to the deactivation of the ZnO/Al2O3 catalysts. Meanwhile, the activity of ZnAl2O4 catalyst was stable for 100 h at 873 K and GHSV of 150,000. The ZnAl2O4 catalyst was developed for the RWReaction of the CAMERE (carbon dioxide hydrogenation to form methanol via a reverse-water-gas-Shift Reaction) process for methanol formation from CO2.
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Carbon dioxide hydrogenation to form methanol via a reverse-water-gas- Shift Reaction (the CAMERE process)
Industrial and Engineering Chemistry Research, 1999Co-Authors: Oh Shim Joo, Alexander Ya Rozovskii, Galina I. Lin, Sung-hwan Han, Kwang-deog Jung, Il Moon, Sung Jin UhmAbstract:The CAMERE process (carbon dioxide hydrogenation to form methanol via a reverse-water-gas-Shift Reaction) was developed and evaluated. The reverse-water-gas-Shift reactor and the methanol synthesis reactor were serially aligned to form methanol from CO2 hydrogenation. Carbon dioxide was converted to CO and water by the reverse-water-gas-Shift Reaction (RWReaction) to remove water before methanol was synthesized. With the elimination of water by RWReaction, the purge gas volume was minimized as the recycle gas volume decreased. Because of the minimum purge gas loss by the pretreatment of RWReactor, the overall methanol yield increased up to 89% from 69%. An active and stable catalyst with the composition of Cu/ ZnO/ZrO2/Ga2O3 (5:3:1:1) was developed. The system was optimized and compared with the commercial methanol synthesis processes from natural gas and coal.
Oh Shim Joo - One of the best experts on this subject based on the ideXlab platform.
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development of zno al2o3 catalyst for reverse water gas Shift Reaction of camere carbon dioxide hydrogenation to form methanol via a reverse water gas Shift Reaction process
Applied Catalysis A-general, 2001Co-Authors: Sang Woo Park, Oh Shim Joo, Kwang-deog Jung, Hyo Kim, Sung-hwan HanAbstract:Abstract ZnO and ZnO/Al2O3 catalysts were studied for a reverse-water-gas-Shift Reaction (RWReaction). The catalytic activities depended on the compositions of Zn and Al at the temperature range of 673–973 K and GHSV of 15,000. The activities were close to the equilibrium conversion at temperatures above 873 K. The catalysts were characterized by using BET, TPR, XRD, SEM, and TEM. The ZnO/Al2O3 catalysts were mixtures of ZnO and ZnAl2O4 phases, and the particle size of the ZnO was strongly dependent on its composition in the ZnO/Al2O3 catalysts. ZnO/Al2O3 (Zn:Al=1:1) catalyst has the smallest particle size of ZnO and its conversion of CO2 at 873 K and GHSV of 150,000 was 43%. The stability of ZnO/Al2O3 catalysts increased in the presence of the large particles of ZnO. Hence, ZnO/Al2O3 (Zn:Al=4:1) catalyst was more stable than the ZnO/Al2O3 (Zn:Al=1:1) catalyst. The conversion of CO2 on the ZnO/Al2O3 (Zn:Al=1:1) catalyst decreased from 43 to 17% in 48 h. The ZnO in ZnO/Al2O3 catalysts was reduced to the Zn metal during the RWReaction, which contributed to the deactivation of the ZnO/Al2O3 catalysts. Meanwhile, the activity of ZnAl2O4 catalyst was stable for 100 h at 873 K and GHSV of 150,000. The ZnAl2O4 catalyst was developed for the RWReaction of the CAMERE (carbon dioxide hydrogenation to form methanol via a reverse-water-gas-Shift Reaction) process for methanol formation from CO2.
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Development of ZnO/Al2O3 catalyst for reverse-water-gas-Shift Reaction of CAMERE (carbon dioxide hydrogenation to form methanol via a reverse-water-gas-Shift Reaction) process
Applied Catalysis A: General, 2001Co-Authors: Sang Woo Park, Oh Shim Joo, Kwang-deog Jung, Hyo Kim, Sung-hwan HanAbstract:Abstract ZnO and ZnO/Al2O3 catalysts were studied for a reverse-water-gas-Shift Reaction (RWReaction). The catalytic activities depended on the compositions of Zn and Al at the temperature range of 673–973 K and GHSV of 15,000. The activities were close to the equilibrium conversion at temperatures above 873 K. The catalysts were characterized by using BET, TPR, XRD, SEM, and TEM. The ZnO/Al2O3 catalysts were mixtures of ZnO and ZnAl2O4 phases, and the particle size of the ZnO was strongly dependent on its composition in the ZnO/Al2O3 catalysts. ZnO/Al2O3 (Zn:Al=1:1) catalyst has the smallest particle size of ZnO and its conversion of CO2 at 873 K and GHSV of 150,000 was 43%. The stability of ZnO/Al2O3 catalysts increased in the presence of the large particles of ZnO. Hence, ZnO/Al2O3 (Zn:Al=4:1) catalyst was more stable than the ZnO/Al2O3 (Zn:Al=1:1) catalyst. The conversion of CO2 on the ZnO/Al2O3 (Zn:Al=1:1) catalyst decreased from 43 to 17% in 48 h. The ZnO in ZnO/Al2O3 catalysts was reduced to the Zn metal during the RWReaction, which contributed to the deactivation of the ZnO/Al2O3 catalysts. Meanwhile, the activity of ZnAl2O4 catalyst was stable for 100 h at 873 K and GHSV of 150,000. The ZnAl2O4 catalyst was developed for the RWReaction of the CAMERE (carbon dioxide hydrogenation to form methanol via a reverse-water-gas-Shift Reaction) process for methanol formation from CO2.
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Carbon dioxide hydrogenation to form methanol via a reverse-water-gas- Shift Reaction (the CAMERE process)
Industrial and Engineering Chemistry Research, 1999Co-Authors: Oh Shim Joo, Alexander Ya Rozovskii, Galina I. Lin, Sung-hwan Han, Kwang-deog Jung, Il Moon, Sung Jin UhmAbstract:The CAMERE process (carbon dioxide hydrogenation to form methanol via a reverse-water-gas-Shift Reaction) was developed and evaluated. The reverse-water-gas-Shift reactor and the methanol synthesis reactor were serially aligned to form methanol from CO2 hydrogenation. Carbon dioxide was converted to CO and water by the reverse-water-gas-Shift Reaction (RWReaction) to remove water before methanol was synthesized. With the elimination of water by RWReaction, the purge gas volume was minimized as the recycle gas volume decreased. Because of the minimum purge gas loss by the pretreatment of RWReactor, the overall methanol yield increased up to 89% from 69%. An active and stable catalyst with the composition of Cu/ ZnO/ZrO2/Ga2O3 (5:3:1:1) was developed. The system was optimized and compared with the commercial methanol synthesis processes from natural gas and coal.
Kwang-deog Jung - One of the best experts on this subject based on the ideXlab platform.
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development of zno al2o3 catalyst for reverse water gas Shift Reaction of camere carbon dioxide hydrogenation to form methanol via a reverse water gas Shift Reaction process
Applied Catalysis A-general, 2001Co-Authors: Sang Woo Park, Oh Shim Joo, Kwang-deog Jung, Hyo Kim, Sung-hwan HanAbstract:Abstract ZnO and ZnO/Al2O3 catalysts were studied for a reverse-water-gas-Shift Reaction (RWReaction). The catalytic activities depended on the compositions of Zn and Al at the temperature range of 673–973 K and GHSV of 15,000. The activities were close to the equilibrium conversion at temperatures above 873 K. The catalysts were characterized by using BET, TPR, XRD, SEM, and TEM. The ZnO/Al2O3 catalysts were mixtures of ZnO and ZnAl2O4 phases, and the particle size of the ZnO was strongly dependent on its composition in the ZnO/Al2O3 catalysts. ZnO/Al2O3 (Zn:Al=1:1) catalyst has the smallest particle size of ZnO and its conversion of CO2 at 873 K and GHSV of 150,000 was 43%. The stability of ZnO/Al2O3 catalysts increased in the presence of the large particles of ZnO. Hence, ZnO/Al2O3 (Zn:Al=4:1) catalyst was more stable than the ZnO/Al2O3 (Zn:Al=1:1) catalyst. The conversion of CO2 on the ZnO/Al2O3 (Zn:Al=1:1) catalyst decreased from 43 to 17% in 48 h. The ZnO in ZnO/Al2O3 catalysts was reduced to the Zn metal during the RWReaction, which contributed to the deactivation of the ZnO/Al2O3 catalysts. Meanwhile, the activity of ZnAl2O4 catalyst was stable for 100 h at 873 K and GHSV of 150,000. The ZnAl2O4 catalyst was developed for the RWReaction of the CAMERE (carbon dioxide hydrogenation to form methanol via a reverse-water-gas-Shift Reaction) process for methanol formation from CO2.
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Development of ZnO/Al2O3 catalyst for reverse-water-gas-Shift Reaction of CAMERE (carbon dioxide hydrogenation to form methanol via a reverse-water-gas-Shift Reaction) process
Applied Catalysis A: General, 2001Co-Authors: Sang Woo Park, Oh Shim Joo, Kwang-deog Jung, Hyo Kim, Sung-hwan HanAbstract:Abstract ZnO and ZnO/Al2O3 catalysts were studied for a reverse-water-gas-Shift Reaction (RWReaction). The catalytic activities depended on the compositions of Zn and Al at the temperature range of 673–973 K and GHSV of 15,000. The activities were close to the equilibrium conversion at temperatures above 873 K. The catalysts were characterized by using BET, TPR, XRD, SEM, and TEM. The ZnO/Al2O3 catalysts were mixtures of ZnO and ZnAl2O4 phases, and the particle size of the ZnO was strongly dependent on its composition in the ZnO/Al2O3 catalysts. ZnO/Al2O3 (Zn:Al=1:1) catalyst has the smallest particle size of ZnO and its conversion of CO2 at 873 K and GHSV of 150,000 was 43%. The stability of ZnO/Al2O3 catalysts increased in the presence of the large particles of ZnO. Hence, ZnO/Al2O3 (Zn:Al=4:1) catalyst was more stable than the ZnO/Al2O3 (Zn:Al=1:1) catalyst. The conversion of CO2 on the ZnO/Al2O3 (Zn:Al=1:1) catalyst decreased from 43 to 17% in 48 h. The ZnO in ZnO/Al2O3 catalysts was reduced to the Zn metal during the RWReaction, which contributed to the deactivation of the ZnO/Al2O3 catalysts. Meanwhile, the activity of ZnAl2O4 catalyst was stable for 100 h at 873 K and GHSV of 150,000. The ZnAl2O4 catalyst was developed for the RWReaction of the CAMERE (carbon dioxide hydrogenation to form methanol via a reverse-water-gas-Shift Reaction) process for methanol formation from CO2.
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Carbon dioxide hydrogenation to form methanol via a reverse-water-gas- Shift Reaction (the CAMERE process)
Industrial and Engineering Chemistry Research, 1999Co-Authors: Oh Shim Joo, Alexander Ya Rozovskii, Galina I. Lin, Sung-hwan Han, Kwang-deog Jung, Il Moon, Sung Jin UhmAbstract:The CAMERE process (carbon dioxide hydrogenation to form methanol via a reverse-water-gas-Shift Reaction) was developed and evaluated. The reverse-water-gas-Shift reactor and the methanol synthesis reactor were serially aligned to form methanol from CO2 hydrogenation. Carbon dioxide was converted to CO and water by the reverse-water-gas-Shift Reaction (RWReaction) to remove water before methanol was synthesized. With the elimination of water by RWReaction, the purge gas volume was minimized as the recycle gas volume decreased. Because of the minimum purge gas loss by the pretreatment of RWReactor, the overall methanol yield increased up to 89% from 69%. An active and stable catalyst with the composition of Cu/ ZnO/ZrO2/Ga2O3 (5:3:1:1) was developed. The system was optimized and compared with the commercial methanol synthesis processes from natural gas and coal.
Sang Woo Park - One of the best experts on this subject based on the ideXlab platform.
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development of zno al2o3 catalyst for reverse water gas Shift Reaction of camere carbon dioxide hydrogenation to form methanol via a reverse water gas Shift Reaction process
Applied Catalysis A-general, 2001Co-Authors: Sang Woo Park, Oh Shim Joo, Kwang-deog Jung, Hyo Kim, Sung-hwan HanAbstract:Abstract ZnO and ZnO/Al2O3 catalysts were studied for a reverse-water-gas-Shift Reaction (RWReaction). The catalytic activities depended on the compositions of Zn and Al at the temperature range of 673–973 K and GHSV of 15,000. The activities were close to the equilibrium conversion at temperatures above 873 K. The catalysts were characterized by using BET, TPR, XRD, SEM, and TEM. The ZnO/Al2O3 catalysts were mixtures of ZnO and ZnAl2O4 phases, and the particle size of the ZnO was strongly dependent on its composition in the ZnO/Al2O3 catalysts. ZnO/Al2O3 (Zn:Al=1:1) catalyst has the smallest particle size of ZnO and its conversion of CO2 at 873 K and GHSV of 150,000 was 43%. The stability of ZnO/Al2O3 catalysts increased in the presence of the large particles of ZnO. Hence, ZnO/Al2O3 (Zn:Al=4:1) catalyst was more stable than the ZnO/Al2O3 (Zn:Al=1:1) catalyst. The conversion of CO2 on the ZnO/Al2O3 (Zn:Al=1:1) catalyst decreased from 43 to 17% in 48 h. The ZnO in ZnO/Al2O3 catalysts was reduced to the Zn metal during the RWReaction, which contributed to the deactivation of the ZnO/Al2O3 catalysts. Meanwhile, the activity of ZnAl2O4 catalyst was stable for 100 h at 873 K and GHSV of 150,000. The ZnAl2O4 catalyst was developed for the RWReaction of the CAMERE (carbon dioxide hydrogenation to form methanol via a reverse-water-gas-Shift Reaction) process for methanol formation from CO2.
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Development of ZnO/Al2O3 catalyst for reverse-water-gas-Shift Reaction of CAMERE (carbon dioxide hydrogenation to form methanol via a reverse-water-gas-Shift Reaction) process
Applied Catalysis A: General, 2001Co-Authors: Sang Woo Park, Oh Shim Joo, Kwang-deog Jung, Hyo Kim, Sung-hwan HanAbstract:Abstract ZnO and ZnO/Al2O3 catalysts were studied for a reverse-water-gas-Shift Reaction (RWReaction). The catalytic activities depended on the compositions of Zn and Al at the temperature range of 673–973 K and GHSV of 15,000. The activities were close to the equilibrium conversion at temperatures above 873 K. The catalysts were characterized by using BET, TPR, XRD, SEM, and TEM. The ZnO/Al2O3 catalysts were mixtures of ZnO and ZnAl2O4 phases, and the particle size of the ZnO was strongly dependent on its composition in the ZnO/Al2O3 catalysts. ZnO/Al2O3 (Zn:Al=1:1) catalyst has the smallest particle size of ZnO and its conversion of CO2 at 873 K and GHSV of 150,000 was 43%. The stability of ZnO/Al2O3 catalysts increased in the presence of the large particles of ZnO. Hence, ZnO/Al2O3 (Zn:Al=4:1) catalyst was more stable than the ZnO/Al2O3 (Zn:Al=1:1) catalyst. The conversion of CO2 on the ZnO/Al2O3 (Zn:Al=1:1) catalyst decreased from 43 to 17% in 48 h. The ZnO in ZnO/Al2O3 catalysts was reduced to the Zn metal during the RWReaction, which contributed to the deactivation of the ZnO/Al2O3 catalysts. Meanwhile, the activity of ZnAl2O4 catalyst was stable for 100 h at 873 K and GHSV of 150,000. The ZnAl2O4 catalyst was developed for the RWReaction of the CAMERE (carbon dioxide hydrogenation to form methanol via a reverse-water-gas-Shift Reaction) process for methanol formation from CO2.
