Development Of Hydroformylation Co Based Heterogeneous Catalyst

Hydroformylation(OXO reaction)is one of the industrially important homogeneous reactions.The conventional hydroformylation homogeneous catalysts have problems such as harsh preparation conditions,difficulty in separation from products,and recycling.Therefore,the development and utilization of heterogeneous catalysts has become a research hotspot in recent years.The most studied among the hydroformylation catalysts is a homogeneous catalyst which the active center metal is Rh and Co.The activity of the Rh-based catalyst is much higher than the Co-based one,but the Rh precious metal is more expensive.Therefore,Co-based catalyst is mostly used in industrial production.This article takes the development of a new heterogeneous catalyst as the starting point.An amorphous Ni-Co-B/SBA-15 supported catalyst modified by Ni metal with SBA-15 as carrier was designed and prepared.The ternary Ni-Co-B amorphous alloy is uniformly distributed on the surface of the carrier SBA-15 with a high specific surface area and a uniformly ordered straight channel.The addition of Ni plays a role in changing the composition of the amorphous alloy and adjusting the electronic structure of Co and B.It not only improves the stability of the amorphous alloy,but also prevents the agglomeration of amorphous particles from affecting the catalytic activity.Based on the characterization of the phase,morphology,texture properties,surface element properties and 1-hexene hydroformylation activity of the prepared samples,the properties of the prepared catalysts were studied.1.Preparation of heterogeneous Ni-B/SBA-15,Co-B/SBA-15 and Ni-Co-B/SBA-15 supported catalysts with different Ni/Co ratios by impregnation and chemical reduction.The preparation methods of catalysts are simple and storage conditions are mild.The samples were evaluated for catalytic activity and a series of characterizations.The results suggested that these catalysts exhibit different activities.The distribution of Ni-Co-B amorphous alloys with different nickel-cobalt molar ratios on the carrier SBA-15 is different.The addition of Ni metal regulates the electronic state of the catalyst and affects the active center.The distribution is therefore different in activity.The Ni-Co-B/SBA-15 catalyst having a Ni/Co molar ratio of 0.75:1 exhibited the best catalytic reactivity.2.The optimum process conditions are:the stirring speed is 1200 rpm,the reaction temperature is 130?,the reaction pressure is 5 MPa and the reaction time is 3 h.Under this condition,the conversion of 1-hexene reached 98.9%,the yield of heptaldehyde reached 91.3%,and the aspect ratio was 1.4.After 5 cycles of the reaction,the catalyst remained in an amorphous structure and the hydroformylation reaction activity did not decrease significantly.It indicated that the catalyst has good reusability.