Activity and selectivity of Group VIII, alkali-promoted Mn-Ni, and Mo-based catalysts for C 2+ oxygenate synthesis from the CO hydrogenation and CO/H 2/C 2H 4 reactions

Abstract

Activity and selectivity of Group VIII metal catalysts, H 2S-treated Group VIII metal catalysts, alkali-promoted Mn-Ni catalysts, and Mo-based catalysts toward higher oxygenates via the CO hydrogenation and ethylene hydroformylation (CO/H 2/C 2H 4) reactions at 545 K and 1 MPa have been studied. The catalysts exhibited a wide range of activity and selectivity for C 2 oxygenate synthesis. The selectivity toward C 2 oxygenates is attributed to the CO insertion capability of the catalyst. All of the catalysts tested, except H 2S-treated Os, exhibited CO insertion activity in the CO/H 2/C 2H 4 reaction leading to C 3 oxygenate formation. Rh and Ru exhibited exceptionally high activity and selectivity for C 2 oxygenates in the CO/H 2 reaction and C 3 oxygenates in the CO/H 2/C 2H 4 reaction. Sulfur treatment of the catalysts poisoned CO dissociation and hydrogenation capability to various degrees for the Group VIII catalysts. Coprecipitated alkali–Mn-Ni catalysts showed low hydrogenation activity and good oxygenate selectivity. Mo-based catalysts showed the poorest activity and selectivity toward higher oxygenates at 1 MPa. Optimization of C 2 oxygenate activity and selectivity requires a proper balance between CO dissociation activity, CO insertion activity, and hydrogenation activity.