Synthesis of aldehydes from synthesis gas over Na-promoted Mn-Ni catalysts

Abstract

The synthesis of acetaldehyde and propionaldehyde from CO hydrogenation over NaMnNi catalysts has been studied. Coprecipitated NaMnNi catalysts exhibited high activities for the synthesis of acetaldehyde from CO hydrogenation and the synthesis' of propionaldehyde from addition of ethylene to CO hydrogenation. In contrast, NaMnNi/SiO 2 catalysts prepared from coimpregnation showed mainly methanation and ethylene hydrogenation activities. The selectivities to acetaldehyde in CO hydrogenation were found to parallel the selectivities to propionaldehyde in ethylene addition. X-ray photoelectron spectroscopic studies revealed that reduction of the coprecipitated NaMnNi catalyst at 350°C led to the migration of Na ions onto the surface of the catalyst resulting in the suppression of hydrogen chemisorption on the catalyst.