Effect of calcium dopant on catalysis of Ir/La2O3 for hydrogen production by oxidative steam reforming of glycerol
The superfluous glycerol derived from biodiesel production can be a low-cost feedstock for hydrogen production via reforming technology. In this work, a La2O3 supported iridium catalyst was employed to catalyze the oxidative steam reforming of glycerol (OSRG) for hydrogen production, in the range of S/C ratio of 1–3, C/O ratio of 0.75–1 and 550–750 °C. The catalyst was modified with Na, Mg and Ca to optimize the catalytic performance in OSRG reaction. It was found that Ca is promising in promoting Ir/La2O3 catalyst for OSRG, offering excellent activity, hydrogen selectivity and stability. By combining multiple techniques, i.e. XRD, FTIR, Raman, XPS, H2-TPR, CO2-TPD and HRTEM, the Ca modified Ir/La2O3 catalyst was characterized to understand the role of Ca promoter. Multi-functions of Ca were demonstrated, including inducing structural defects of La2O2CO3, endowing the catalyst strong basicity and tuning the metal–support interaction, which make the catalyst highly resistant to coking and sintering, therefore performing excellent long-term stability for 100 h.
Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Ir/La2O3 efficiently catalyzes oxidative steam reforming of glycerol. ► Ca as promoter improves stability of Ir/La2O3. ► Ca doping in La2O2CO3 eliminates coking. ► Ca improves the dispersion of catalyst via strong metal–support interaction.
Journal: Applied Catalysis B: Environmental - Volume 127, 30 October 2012, Pages 89–98