Catalisadores à base de índia e zircônia na obtenção do isobuteno a partir do etanol

Abstract

Ethanol is a platform molecule able of generating different products or chemical intermediates type "drop in", that is, identical to those generated by the petrochemical, but in one reactional stage and using multifunctional catalysts. The isobutene, important olefin used in different industrial sectors, is one of these compounds. The main route of obtaining the Isobutene is the cracking of nafta. Recently, a pioneering work has shown that it is possible to synthesize isobutene from ethanol in one step employing In2O3/ZrO2. Thus, the purpose of this contribution is to expand the information base on this synthesis and cited catalytic system employing In2O3 in different contents and supports. The catalysts were characterized by chemisorption of N2, XRD, XPS, ICP-OES, electron microscopy, TPD-H2O, TPD-ethanol, TPR and isopropanol conversion reaction. Comparing with other supports usually used it was observed that m-ZrO2 the best performance for the generation of isobutene from ethanol. Already the In2O3 supported on silica synthesizes only acetaldehyde. It has been observed that acetaldehyde and acetone are the relative intermediates of this reaction. The production of acetone in the catalysts is associated with the redox properties of these samples, and the basic acids with the selectivity to isobutene. In addition, it has been confirmed that isobutene is the final product of the cascade reaction and is formed only at longer contact times.