The role of chromium in iron-based high-temperature water-gas shift catalysts under industrial conditions
نویسندگان
چکیده
Chromium promotion of iron oxide based water-gas shift (WGS) catalysts prepared via co-precipitation/calcination was investigated. Mössbauer spectroscopy and XRD evidence that chromium is incorporated in the calcined hematite (?-Fe2O3) precursor irrespective doping level (0?12 wt.%). CO-TPR shows delays reduction active magnetite (Fe3O4) phase. WGS activity evaluated under realistic conditions for 4 days. Enhanced CO conversion observed with increased doping. spectra indicate incorporates into octahedral sites prevents Fe3+ to Fe2+ during formation phase, leading an Fe3+/Fe2+ ratio sites. The higher did not affect high associated structural stabilization mechanism Cr-doping. Interpretation supported by computational modelling various vacancy-doped structures. bulk structure situ chromium-doped high-temperature catalyst best described as a partially oxidized No surface effects Cr-doping were found.
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ژورنال
عنوان ژورنال: Applied Catalysis B-environmental
سال: 2021
ISSN: ['1873-3883', '0926-3373']
DOI: https://doi.org/10.1016/j.apcatb.2021.120465