Structure-Activity Relationship of Gold Catalysts on Alumina Supported Cu-Ce Oxides for CO and Volatile Organic Compound Oxidation

Authors: Tatyana T. Tabakova, Elitsa N. Kolentsova, Dimitar Y. Dimitrov, Krasimir I. Ivanov, Yordanka G. Karakirova, Petya Cv. Petrova, Georgi V. Avdeev

Abstract:

The catalytic oxidation of CO and volatile organic compounds (VOCs) is considered as one of the most efficient ways to reduce harmful emissions from various chemical industries. The effectiveness of gold-based catalysts for many reactions of environmental significance was proven during the past three decades. The aim of this work was to combine the favorable features of Au and Cu-Ce mixed oxides in the design of new catalytic materials of improved efficiency and economic viability for removal of air pollutants in waste gases from formaldehyde production. Supported oxides of copper and cerium with Cu: Ce molar ratio 2:1 and 1:5 were prepared by wet impregnation of g-alumina. Gold (2 wt.%) catalysts were synthesized by a deposition-precipitation method. Catalysts characterization was carried out by texture measurements, powder X-ray diffraction, temperature programmed reduction and electron paramagnetic resonance spectroscopy. The catalytic activity in the oxidation of CO, CH₃OH and (CH₃)₂O was measured using continuous flow equipment with fixed bed reactor. Both Cu-Ce/alumina samples demonstrated similar catalytic behavior. The addition of gold caused significant enhancement of CO and methanol oxidation activity (100 % degree of CO and CH₃OH conversion at about 60 and 140 ^oC, respectively). The composition of Cu-Ce mixed oxides affected the performance of gold-based samples considerably. Gold catalyst on Cu-Ce/γ-Al₂O₃ 1:5 exhibited higher activity for CO and CH₃OH oxidation in comparison with Au on Cu-Ce/γ-Al₂O₃ 2:1. The better performance of Au/Cu-Ce 1:5 was related to the availability of highly dispersed gold particles and copper oxide clusters in close contact with ceria.

Keywords: CO and VOCs oxidation, copper oxide, ceria, gold catalysts.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1131289

References:

[1] J. Li, H. Liu, Y. Deng, G. Liu, Y. Chen, and J. Yang, “Emerging nanostructured materials for the catalytic removal of volatile organic compounds,” Nanotechnology Reviews, vol. 5, no 1, pp. 147–181, 2016.
[2] M. S. Kamal, S. A. Razzak, and M. M. Hossain, “Catalytic oxidation of volatile organic compounds (VOCs): A review,” Atmospheric Environment, vol. 140, pp. 117-134, 2016.
[3] Z. Zhang, Z. Jiang, and W. Shangguan, “Low-temperature catalysis for VOCs removal in technology and application: A state-of-the-art review,” Catalysis Today, vol. 264, pp. 270-278, 2016.
[4] L. F. Liotta, “Catalytic oxidation of volatile organic compounds on supported noble metals,” Applied Catalysis B, vol. 100, pp. 403-412, 2010.
[5] G. Avgouropoulos, and T. Tabakova, Environmental Catalysis over Gold-Based Materials, RSC Catalysis Series, no 13, RSC Publishing, Thomas Graham House, Cambridge, 2013.
[6] S. Scire, and L. F. Liotta, “Supported gold catalysts for the total oxidation of volatile organic compounds,” Applied Catalysis B, vol. 125, pp. 222–246, 2012.
[7] M. Stoyanova, D. Petrov, D. Dimitrov, K. Ivanov, and S. Christoskova, “Nanocomposite oxide systems for oxidation of CO and VOCs in gaseous phase, Journal of International Scientific Publications: Ecology and Safety, vol. 8, pp. 479-486, 2014.
[8] L. F. Liotta, H. Wu, G. Pantaleo, and A. M. Venezia, “Co3O4 nanocrystals and Co3O4-MOx binary oxides for CO, CH4 and VOC oxidation at low temperatures: A review,” Catalysis Science & Technology, vol. 3, pp. 3085–3102, 2013.
[9] P.-O. Larsson, and A. Andersson, “Oxides of copper, ceria promoted copper, manganese and copper manganese on Al2O3 for the combustion of CO, ethyl acetate and ethanol,” Applied Catalysis B, vol. 24, pp. 175–192, 2000.
[10] H. Wan, D. Li, Y. Dai, Y. Hu, Y. Zhang, L. Liu, et al., “Effect of CO pretreatment on the performance of CuO/CeO2/-Al2O3 catalysts in CO + O2 reactions,” Applied Catalysis A, vol. 360, pp. 26–32, 2009.
[11] M. Konsolakis, “The role of copper–ceria interactions in catalysis science: Recent theoretical and experimental advances,” Applied Catalysis B, vol. 198, pp. 49–66, 2016.
[12] D. Delimaris, and T. Ioannides, “VOC oxidation over CuO–CeO2 catalysts prepared by a combustion method,” Applied Catalysis B, vol. 89, pp. 295–302, 2009.
[13] M. Piumetti, S. Bensaid, T. Andana, N. Russo, R. Pirone, and D. Fino, “Cerium-copper oxides prepared by solution combustion synthesis for total oxidation reactions: From powder catalysts to structured reactors,” Applied Catalysis B, vol. 205, pp. 455–468, 2017.
[14] A. Trovarelli, and P. Fornasiero, “Catalysis by Ceria and Related Materials – 2nd Edition,” Imperial College Press, London, 2013.
[15] E. Kolentsova, D. Dimitrov, K. Ivanov, T. Tabakova, Y. Karakirova, K. Tenchev, G. Avdeev, “CO and VOCs oxidation over alumina supported Cu-Mn catalysts modified by cerium,“ Bulgarian Chemical Communications, to be published.
[16] M. Gonzalez Castaño, T. R. Reina, S. Ivanova, M. A. Centeno, and J. A. Odriozola, “Pt vs. Au in water–gas shift reaction,” Journal of Catalysis, vol. 314, pp. 1–9, 2014.
[17] H. C. Yao and Y. F. Yu Yao, “Ceria in automotive exhaust catalysts: I. Oxygen storage,” Journal of Catalysis, vol. 86, pp. 254-256, 1984.
[18] A. Ishikawa, M. Neurock, and E. Iglesia, “Structural Requirements and Reaction Pathways in Dimethyl Ether Combustion Catalyzed by Supported Pt Clusters,” J. Am. Chem. Soc., vol. 129, pp. 13201-13212, 2007.
[19] A. Ishikawa and E. Iglesia, “Bifunctional pathways mediated by Pt clusters and Al2O3 in the catalytic combustion of dimethyl ether,” Chemical Communications, pp. 2992- 2993, 2007.