The effect of Fe on the catalytic performance of Rh–Mn–Li/SiO2 catalyst: A DRIFTS study

Different amounts of Fe promoted Rh–Mn–Li/SiO2 catalysts were prepared and investigated for the synthesis of C2 oxygenates from syngas. The results showed that the low amount of Fe (≤ 0.1 wt.%) improved the reactivity and yield of C2+ oxygenates, but an opposite effect appeared at high content of Fe (> 0.1 wt.%). Diffuse reflectance infrared Fourier transform spectroscopy was used to probe the effects of Fe on CO adsorption and hydrogenation, and two opposing effects were evidenced. Moreover, it is proposed that the facile transformation of dicarbonyl Rh+(CO)2 into H–Rh–CO is responsible for high selectivity of C2+ oxygenates.

Different amounts of Fe promoted Rh–Mn–Li/SiO2 catalysts were prepared and investigated for the synthesis of C2 oxygenate from syngas, and the CO conversion and C2 oxygenate selectivity are strongly influenced by the amounts of Fe.Figure optionsDownload as PowerPoint slideHighlights
► The Rh-Mn-Li/SiO2 catalysts promoted with different amounts of Fe were prepared.
► The effect of Fe on CO hydrogenation over Rh-Mn-Li-Fe/SiO2 catalysts was studied.
► The doping of Fe decreased the CO adsorption, further decreased CO conversion.
► Fe doping increased the transform rate of adsorbed CO, so promoted the reaction.