Sulphated Zirconia Catalyst Prepared from Solid Sulphates by Non-aqueous Method

Document Type: Research Note

Authors

1 Chemical Engineering Department, Federal University of Technology, Minna, Niger State, Nigeria

2 Chemical and Petroleum Engineering, Niger Delta University, Wilberforce Island, Bayelsa State, Nigeria

3 Elem close off Rumuibekwe Road, Rumurolu Port Harcourt, River State, Nigeria

Abstract

Non-crystallinesulphated zirconia catalysts were synthesised by a non-aqueous and non-conventional method. The effect of varying the molar ratio of sulphating agent to zirconium source was also investigated. The samples were characterized by X-ray diffraction, Energy Dispersive X-ray (EDX), Infra-red Spectroscopy (IR),X-ray Photoelectron Spectroscopy (XPS). The surface acidity was measured by the Pyridine-DRIFTS (Diffuse Reflectance Infrared Fourier Transform Spectroscopy) technique. The structural and textural properties of the sulphated zirconia were studied. The EDX and XPS profiles suggested that both sulphated zirconia catalysts have similar zirconia and sulphate structures; however, both catalysts were amorphous. Deconvolution of their XPS O 1s spectra showed that the samples contained both oxide oxygen of zirconium and sulphate oxygen, which sample I showed a higher amount of sulphate oxygen. Adsorption of pyridine into the samples indicated that the higher amounts of Brönsted acid sites are presented in sample I with lower amount of sulphate during preparation. This opens up the possibility of controlling the degree and type of active sites on a catalyst by the amount of sulphate used for preparation. Sulphated zirconia catalyst with higher activity properties was achieved via a non-aqueous, environmentalfriendly method. The zirconia catalyst has great contribution towards energy production which is used for preparation and trans-esterification of fatty acids for production of biodiesel.

Keywords


1.     Hino, M., M. Kurashige, H. Matsuhashi and K. Arata, 2006. The surface structure of sulfated zirconia: Studies of XPS and thermal analysis. Thermochimica acta, 441(1): 35-41.
2.     Yadav, G.D. and A.D. Murkute, 2004. Preparation of a novel catalyst UDCaT-5: enhancement in activity of acid-treated zirconia—effect of treatment with chlorosulfonic acid vis-à-vis sulfuric acid. Journal of Catalysis, 224(1): 218-223.
3.     Song, X. and A. Sayari, 1996. Sulfated zirconia-based strong solid-acid catalysts: Recent progress. Catalysis Reviews - Science and Engineering, 38(3): 329-412.
4.     Davis, B.H., R.A. Keogh and R. Srinivasan, 1994. Sulfated zirconia as a hydrocarbon conversion catalyst. Catalysis Today, 20(2): 219-256.
5.     Ezekoye, B., F. Ezema, V. Ezekoye, P. Offor and U. Uduh, 2014. Synthesis, structural and surface morphological characterizations of sulfated zirconia Nanoparticles via chemical route. Nigerian Journal of Technology, 33(1): 54-59.
6.     Rattanaphra, D., A. Harvey and P. Srinophakun, 2010. Simultaneous conversion of triglyceride/free fatty acid mixtures into biodiesel using sulfated zirconia. Topics in Catalysis, 53(11-12): 773-782.
7.     Nascimento, P., C. Akratopoulou, M. Oszagyan, G. Coudurier, C. Travers, J. Joly and J. Vedrine, 1993. ZrO 2-SO 4 2-Catalysts. Nature and Stability of Acid Sites Responsible for n-Butane Isomerization. Studies in Surface Science and Catalysis, 75: 1185-1197.
8.     Grecea, M.L., A.C. Dimian, S. Tanase, V. Subbiah and G. Rothenberg, 2012. Sulfated zirconia as a robust superacid catalyst for multiproduct fatty acid esterification. Catalysis Science & Technology, 2(7): 1500-1506.
9.     Sun, Y., S. Ma, Y. Du, L. Yuan, S. Wang, J. Yang, F. Deng and F.S. Xiao, 2005. Solvent-free preparation of nanosized sulfated zirconia with brønsted acidic sites from a simple calcination. Journal of Physical Chemistry B, 109(7): 2567-2572.
10.   Moulder, J., 1995. stickle WF, Sobol PE, Bomben KD. Handbook of X-ray photoelectron spectroscopy. Physical Electronics Inc: 180-181.
11.   Eterigho, E.J., T. Farrow and C. Ogbuka, 2014. Effect of Modification on Conventional Preparation Method for Sulphated Zirconia on the Production of Fatty Acid Methyl Ester. Asian Journal of Engineering and Technology, 2(3).