Avaliação de catalisadores de Cu e K2O suportados em CeO2 e Nb2O5 utilizados em reações de reforma a vapor do metanol para a obtenção de hidrogênio

Abstract

The pollution caused by the burning of fossil fuels has made the study of renewable and less polluting fuels be, even more, encouraged. One of the clean energy sources of the world is the technology of using hydrogen in fuel cells. The methanol’s steam reforming is an important process for generating hydrogen, which has been widely used in the industry, as it is considered easy to obtain. The main objective of this project is to evaluate three different types of catalysts, Cu-K2O/Nb2O5/CeO2, Cu- K2O/Nb2O5 and Cu-K2O/CeO2 in reactions of steam reforming of methanol, as his conversion, selectivity and hydrogen yield. The catalytic tests were made in a reaction unit at a constant temperature of 573K, the catalyst bed of 3.5 g and a molar ratio H 2 O: CH 3 OH equal to 1:1. Gaseous products and liquid products from the reaction were analyzed, to evaluating the level of hydrogen production and carbon dioxide, as well as the formation of undesirable byproducts, such as, for example, methane. The synthesized catalysts were characterized by methods of textural analysis of the catalyst - which proved that the nature of the support exerts great influence on the surface area of the catalyst - scanning electron microscopy (SEM) - which it was observed that there was good distribution of catalytic metals on the surface - and X-ray diffraction (XRD) - which proved the desired crystalline phase of the compounds present in the catalysts. The catalytic tests present, for the three catalysts, good selectivity to hydrogen and methanol’s conversion. The catalytic tests showed, for the three catalysts, good selectivity to hydrogen and methanol’s conversion, however, the reaction yields obtained were extremely low, which implies the impossibility of the catalysts studied in the reaction of steam reforming of methanol.