A series of copper ion substituted MAl2O4 (M= Mg, Mn, Fe and Zn) spinels is prepared by a single step solution combustion synthesis (SCS) and tested for methanol steam reforming (MSR). The copper ion substituted Cu0.1Fe0.9Al2O4 appears to be the most active, showing ~98% methanol conversion at 300 °C with ~5% CO selectivity at GHSV= 30000 h-1 and H2O:CH3OH= 1.1. The analogous impregnated catalyst, CuO (10 at.%)/FeAl2O4, is found to be much less active. These materials are characterized by XRD, H2-TPR, BET, HRTEM, XPS and XANES analyses. Spinel phase formation is highly facilitated upon Cu-ion substitution, and Cu loading beyond 10 at.% leads to the formation of CuO as an additional phase. The ionic substitution of copper in FeAl2O4 leads to the highly crystalline SCS catalyst containing Cu 2+ ion sites that are shown to be more active than the dispersed CuO nano-crystallites on the FeAl2O4 impregnated catalyst, despite its lower surface area. The as prepared SCS catalyst contains also a portion of copper as Cu 1+ that increases when subjected to reforming atmosphere. The MSR activity of the SCS catalyst decreases with time-on-stream due to the sintering of catalyst crystallites as established from XPS and HRTEM analyses.

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Here we report, the sol–gel synthesized, microstructural analysis, surface and magnetic properties of solid solutions of Fe1−xCuxAl2O4.

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