由HRuCo_3(CO)_(12)制备的催化剂上CO加氢反应中含氧产物分布与表面酰基的关系

由HRuCo_3(CO)_(12)制备的催化剂在CO加氢反应中,若在初始阶段或温度较低的条件下,含氧产物大部分是甲醇;若增加反应时间或提高反应温度,C_2含氧化合物则是主要产物。原位红外光谱揭示了甲酰基和乙酰基分别是形成甲醇和C_2含氧化合物的中间体,而且乙酰基来自甲酰基与甲基的相互工作用。

RELATIONSHIP BETWEEN OXYGENATE DISTRIBUTION AND SURFACE ACYL SPECIES IN CO HYDROGENATION OVER SILICA-SUPPORTED HRuCo_3(CO)_(12) BIMETALLIC CARBONYL CLUSTER-DERIVED CATALYST

In CO hydrogenation over silica-supported HRuCo3(CO)12 bimetallic carbonyl cluster-derived catalyst, at the initial stage (or low temperature) the oxygenate products mainly consisted of methanol, and by increasing the reaction time (or temperature) C2-oxygenates including ethanol and acetaldehyde were preeminent above other oxygenates.In situ IR spectra revealed that at the initial stage of CO hydrogenation, a band at 1584 cm-1 assigned to surface formyl species appeared.Increasing the reaction time (or temperature) resulted in the appearance of 1555 cm-1 assigned to acetyl species.It is suggested that the bands of species at 1584 and 1555 cm-1 are very important intermediates to produce methanol and C2-oxygenates respectively, and the acetyl group possibly results from the interaction of formyl with -CH2- species.