Abstract
The conversion of bioethanol over supported oxide catalysts (CuO, ZnO, Cr2O3, CeO2) was studied, among which the most active in the production of hydrogen is 3% CuO/γ-Al2O3. Modification of 3% CuO/γ-Al2O3 catalyst with Cr2O3, ZnO and CeO2 promotes the growth of hydrogen yield. The highest concentration of hydrogen at 300° C and a space velocity of 1 h-1 on CuO-ZnO / γ-Al2O3 was 48% by volume. The acidity of catalysts for adsorption-desorption of pyridine by infrared spectroscopy (ITI Matson FTIR) was determined. When the content of CuO in the catalyst is increased from 1 to 3%, the amount of Lewis acidic centers (LAS) increases from 58 to 82 μmol/gcat. Modification with chromium oxide of the copper catalyst increases the number of LAS from 82 to 156 μmol/gcat by adsorption of pyridine at 150° C and from 79 to 120 μmol/gcat with pyridine adsorption at 250 °C. It has been established that an increase in the number of Lewis acid sites has a positive effect on the yield of hydrogen in the conversion of bioethanol. According to electron microscopy, the modification of catalysts leads to an increase in the dispersity of the catalyst and to a uniform distribution of particles on the surface of the catalyst, which also contributes to its greater activity in the production of hydrogen.