Spinel-type MnxCr3-xO4-based catalysts for ethanol steam reforming

For catalysts comprised of mixed manganese-chromium oxides MnxCr3-xO4 (x=0.3-2.7) prepared by Pechini route with Ni and Ru supported by impregnation fundamental factors determining their performance in ethanol steam reforming have been elucidated using combination of structural (XRD, HRTEM), spectroscopic (UV-vis), surface science (XPS, FTIR spectroscopy of adsorbed CO) and kinetic (H-2 and EtOH TPR, oxygen isotope heteroexchange with (CO2)-O-18) methods. The most important feature is strong metal-support interaction stabilizing small clusters of metals/alloys and preventing carbon nucleation. The lattice oxygen mobility and reactivity increased with Mn content. The highest TOF was obtained for (Ni + Ru)-loaded oxide support containing cubic spinel phase of MnCr2O4 composition, which implies a positive effect of Ni-Ru interaction in mixed clusters on catalytic activity. This catalyst has also a high density of active sites, surface enriched by Mn and sufficient oxygen mobility providing coking stability, which makes it attractive for practical application.

Automated summary

This study elucidates the fundamental factors determining the performance of manganese-chromium oxides catalysts in ethanol steam reforming, with a focus on metal-support interaction, lattice oxygen mobility, and the positive effect of Ni-Ru interaction on catalytic activity. The catalyst with the highest TOF is a (Ni + Ru)-loaded oxide support containing cubic spinel phase of MnCr2O4 composition, which exhibits high density of active sites, surface enrichment by Mn, and sufficient oxygen mobility providing coking stability, making it attractive for practical application.