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All Journal Bulletin of Chemical Reaction Engineering & Catalysis Bulletin of Chemical Reaction Engineering & Catalysis
Mardwita Mardwita
Chemical Engineering Department, Faculty of Engineering, Universitas Muhammadiyah Palembang
Chemical Engineering, Chemistry & Bioengineering Chemistry

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Effects of Calcination Temperatures on The Catalytic Activities of Alumina Supported Cobalt and Chromium Catalysts Mardwita Mardwita; Eka Sri Yusmartini; Nidya Wisudawati
Bulletin of Chemical Reaction Engineering & Catalysis 2019: BCREC Volume 14 Issue 3 Year 2019 (December 2019)
Publisher : Department of Chemical Engineering - Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (659.221 KB) | DOI: 10.9767/bcrec.14.3.4673.654-659

Abstract

Catalysts properties are important for catalytic reactions. The interaction between support and metal in a catalyst is resulted from catalyst preparation. In this study, gamma-alumina (Al2O3) supported cobalt (Co) and chromium (Cr) catalysts were prepared by impregnation method and calcined at two different temperatures, they are 400 °C for 4 hours and 800 °C for 4 hours. The resulted catalysts contained 10 wt.% of metal and denoted as Co/Al2O3(400), Co/Al2O33(800), Cr/Al2O3(400), and Cr/Al2O3(800) catalysts. The surface and state of the catalysts were examined by using x-ray diffraction (XRD), x-ray photoelectron spectrometer (XPS) and transmission electron microscopy (TEM). The XRD result reveals that strong interaction between Co and Al2O3 due to a formation of higher cobalt oxide. The XRD result further indicates aggregation and strong support metal interaction between Co and Al2O3 during calcination. On the other hand, TEM result showed that large Co particle was observed on Al2O3. The Cr/Al2O3 catalysts were characterized by using XPS. The XPS results showed that Cr/Al2O3(800) catalyst was dominated by Cr6+ species at binding energy 579.04 eV, indicating high dispersion of Cr on Al2O3. Moreover, Cr metal particle was not observed on XRD and TEM image. All the characterization results provide information that the impregnated metal on Al2O3 showed different properties. Co metal particle tends to be more oxidized and formed large particle, however it was not observed on Cr metal particle. 
Effects of Cobalt and Chromium Loadings to The Catalytic Activities of Supported Metal Catalysts in Methane Oxidation Mardwita Mardwita; Eka Sri Yusmartini; Nidya Wisudawati
Bulletin of Chemical Reaction Engineering & Catalysis 2020: BCREC Volume 15 Issue 1 Year 2020 (April 2020)
Publisher : Department of Chemical Engineering - Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.15.1.6320.213-220

Abstract

A series of alumina supported cobalt and chromium catalysts with different metal loadings were prepared by impregnation method. Six types of alumina supported cobalt and chromium catalysts contained 5 wt%, 10 wt%, and 15 wt% loadings were produced and tested in methane oxidation. The catalysts were characterized by using x-ray diffraction (XRD) and carbon monoxide chemisorption (CO chemisorption). The XRD results do not confirmed any features of cobalt and chromium metal. The metal sizes for both catalysts were larger in high loading as shown by CO chemisorption results. Methane conversion results showed that the conversion increases with increasing the metal loading, however supported chromium catalysts were higher in activities compared to supported cobalt catalysts. Thermal stability tests on 15 wt% Co/Al and 15 wt% Cr/Al catalyst showed that supported chromium catalyst is more stable and maintain the particle size due to its strong interaction with support, while supported cobalt catalyst decrease in methane conversion due to deactivation of the catalyst. Copyright © 2020 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0). 
Effects of Calcination Temperatures on The Catalytic Activities of Alumina Supported Cobalt and Chromium Catalysts Mardwita Mardwita; Eka Sri Yusmartini; Nidya Wisudawati
Bulletin of Chemical Reaction Engineering & Catalysis 2019: BCREC Volume 14 Issue 3 Year 2019 (December 2019)
Publisher : Masyarakat Katalis Indonesia - Indonesian Catalyst Society (MKICS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.14.3.4673.654-659

Abstract

Catalysts properties are important for catalytic reactions. The interaction between support and metal in a catalyst is resulted from catalyst preparation. In this study, gamma-alumina (Al2O3) supported cobalt (Co) and chromium (Cr) catalysts were prepared by impregnation method and calcined at two different temperatures, they are 400 °C for 4 hours and 800 °C for 4 hours. The resulted catalysts contained 10 wt.% of metal and denoted as Co/Al2O3(400), Co/Al2O33(800), Cr/Al2O3(400), and Cr/Al2O3(800) catalysts. The surface and state of the catalysts were examined by using x-ray diffraction (XRD), x-ray photoelectron spectrometer (XPS) and transmission electron microscopy (TEM). The XRD result reveals that strong interaction between Co and Al2O3 due to a formation of higher cobalt oxide. The XRD result further indicates aggregation and strong support metal interaction between Co and Al2O3 during calcination. On the other hand, TEM result showed that large Co particle was observed on Al2O3. The Cr/Al2O3 catalysts were characterized by using XPS. The XPS results showed that Cr/Al2O3(800) catalyst was dominated by Cr6+ species at binding energy 579.04 eV, indicating high dispersion of Cr on Al2O3. Moreover, Cr metal particle was not observed on XRD and TEM image. All the characterization results provide information that the impregnated metal on Al2O3 showed different properties. Co metal particle tends to be more oxidized and formed large particle, however it was not observed on Cr metal particle. 
Effects of Cobalt and Chromium Loadings to The Catalytic Activities of Supported Metal Catalysts in Methane Oxidation Mardwita Mardwita; Eka Sri Yusmartini; Nidya Wisudawati
Bulletin of Chemical Reaction Engineering & Catalysis 2020: BCREC Volume 15 Issue 1 Year 2020 (April 2020)
Publisher : Masyarakat Katalis Indonesia - Indonesian Catalyst Society (MKICS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.15.1.6320.213-220

Abstract

A series of alumina supported cobalt and chromium catalysts with different metal loadings were prepared by impregnation method. Six types of alumina supported cobalt and chromium catalysts contained 5 wt%, 10 wt%, and 15 wt% loadings were produced and tested in methane oxidation. The catalysts were characterized by using x-ray diffraction (XRD) and carbon monoxide chemisorption (CO chemisorption). The XRD results do not confirmed any features of cobalt and chromium metal. The metal sizes for both catalysts were larger in high loading as shown by CO chemisorption results. Methane conversion results showed that the conversion increases with increasing the metal loading, however supported chromium catalysts were higher in activities compared to supported cobalt catalysts. Thermal stability tests on 15 wt% Co/Al and 15 wt% Cr/Al catalyst showed that supported chromium catalyst is more stable and maintain the particle size due to its strong interaction with support, while supported cobalt catalyst decrease in methane conversion due to deactivation of the catalyst. Copyright © 2020 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0). 
Co-Authors Eka Sri Yusmartini Nidya Wisudawati