Catalysts evaluation CuO/n-type semiconductor oxide/Al2O3 in ethanol steam reforming reaction for obtaining hydrogen to fuel cell

Abstract

The electric power generation, and hydrogen as a vector, in fuel cells, is a process of high energy efficiency and low environmental impact. However, hydrogen production has its still high cost, because the H 2 gas is not available in nature. Therefore, we study the steam reforming reaction of ethanol for the production of H 2 , featuring an environmentally friendly process, with low CO 2 emissions in nature as well as being economically viable in Brazil, a major world producer of ethanol. Assuming the reform of ethanol follows similar mechanism to the methanol reforming, whose catalyst for industrial use is composed of Cu/ZnO/Al 2 O 3 , it can be considered that copper catalysts on n-type semiconductor oxide should be effective in reforming reaction ethanol. Thus, replacement of zinc oxide of niobium pentoxide, both characteristics semicondução n-type catalysts may generate similarly. In this work study the performance of the catalysts Cu/ZnO/Al 2 O 3 (commercial catalyst HiFUEL Alfa Aesar) and Cu/Nb 2 O 5 /Al 2 O 3 in the ethanol steam reforming reaction. The catalysts were characterized by adsorption/desorption of N 2 and NH 3 -TPD analysis. The catalytic tests were carried out using a mixture of water:ethanol in a molar ratio equal to 10:1, reactant liquid flow rate of 1 ml/min to 573K. The gaseous product was analyzed on-line by gas chromatography. Results of the textural analysis show that the synthesized catalyst has a specific surface area about three times greater than the commercial catalyst, which has micropores on its surface. For NH 3 -TPD analysis it showed that the strongest acid sites are the commercial catalyst than in the synthesized catalysts. This may occur due to the provision of