Catalytic hydrogen production from 2-propanol in supercritical water: Comparison of some metal catalysts

The gasification of organics in supercritical water is a promising method for the direct production of hydrogen at high pressures, and in order to improve the hydrogen yield or selectivity, activities of various catalysts are evaluated. In this study, hydrogen production from 2-propanol over Ni/Al ₂O₃ and Fe-Cr catalysts was investigated in supercritical water. The experiments were carried out in the temperature range of 400-600 °C and in the reaction time range of 10-30 s, under a pressure of 25 MPa. The hydrogen yields and selectivities of Ni/Al₂O₃ and Fe-Cr used in this study, and those of Pt/Al₂O₃ and Ru/Al₂O₃ used in our previous work were compared. The hydrogen contents of the gaseous products obtained by using Ni/Al ₂O₃ and Fe-Cr were measured as 62 mol% and 70 mol%, respectively, at low temperatures and reaction times. However, the hydrogen yields remained in low levels when compared with that of Pt/Al₂O ₃ used in previous study. Pt/Al₂O₃ was established to be the most effective and selective catalyst for hydrogen production. During the catalytic gasification of a 0.5 M solution of 2-propanol, hydrogen content up to 96 mol% and hydrogen yield of 1.05 mol/mol 2-propanol were obtained.