Catalysts clay-based

Previous studies carried out with clay based catalysts pillared by Fe hydroxo complexes [13] or mixed (Al-Cu or Al-Fe) complexes, have shown that the mixed PILCs lead to the most promising results for organic compounds total oxidation in water, by using hydrogen peroxide as oxidant [14-16],... 

Houdry The first catalytic petroleum cracking process, based on an invention by E. J. Houdiy in 1927, which was developed and commercialized by the Houdry Process Corporation. The process was piloted by the Vacuum Oil Company, Paulsboro, NJ, in the early 1930s. The catalyst was contained in a fixed bed. The first successful catalyst was an aluminosilicate mineral. Subsequently, other related catalysts were developed by Houdry in the United States, by I. G. Farbenindustrie in Germany, and by Imperial Chemical Industries in England. After World War II, the clay-based catalysts were replaced by a variety of synthetic catalysts, many based on alumino-silicates. Later, these too were replaced by zeolites. U.S. Patents 1,837,963 1,957,648 1,957,649. 

Mordenite etc. Dodecatungstophosphoric acid (DTPA) and the ion exchange resin catalysts showed maximum activities. Clay based catalysts and sulphated zirconia showed a moderate activity. Zeolites did not demonstrate any activity to the reaction due to pore size restriction. A 100% selectivity towards the ortho product (l-acetyl-2-methoxy naphthalene) was observed for almost all the reactions for all the catalysts. The para product (2-methoxy-6-acetyl naphthalene) was formed when the aluminium chloride was used as a homogeneous catalyst with nitrobenzene as the solvent. The reaction product was isolated and conformed by the melting point, FT-IR, H-NMR, etc. The reaction is intraparticle diffusion limited. A different catalyst would be required to get p-product selectively. 

The high surface area of clays also makes them particularly attractive as catalyst and reagent supports. Discussion in this chapter will be largely confined to clay-based catalysts in which metal complexes or other ions are specifically incorporated in the clay matrix. Other clay-based catalytic materials will be discussed in Chapter 4. 

The manufacture of these clay-based catalysts consisted of crushing, drying and sizing the raw clay. The sized clay was then formed into slurry followed by washing. The sized clay was dewatered, dried, ground and sized as the final steps in the process (55). This clay catalyst could then be further formed into cylinders or beads depending on the final usage. 

Scheme 11.3 Schematic representation of the polymerization behavior with in-situ protocol, (upper) and tunnel protocol (bottom) clay-based catalysts.

Herney-Ramfrez, J. and Madeira, L. (2010). Use of Pillared Clay-based Catalysts for Wastewater Treatment Through Fenton-hke Processes, in A. GU, S. Korili, R. Trujillano, et al. (eds). Pillared Clays and Related Catalysts, Springer, Heidelberg, Germany, pp. 129—166. 

Preparation by acylation of resorcinol with phenylacetyl chloride in boiling ethylene dichloride (84°), using a series of clay based catalysts (KSF, KSF/0, KPIO, KIO, KO, KS) (65-81%) [5252], (60%) [5253]. 

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