Catalytic Performance Of Supported Ni-Co-B For Hydroformylation Of 1-hexene

Hydroformylation enables olefins to convert into aldehydes.Homogeneous Rh catalysts are expensive and difficult to separate.In this paper,promoting effect of supporters on heterogeneous Co amorphous alloy catalysts was studied to improve the catalytic activity.First,different type supporters were employed to load bimetal Ni-Co-B,and their activity for hydroformylation of 1-hexene was compared.Then,the catalytic activity of activated carbon(AC)supported Ni-Co-B was studied to develop the applicable catalysts.Conclusions are as follows:Ni-Co-B amorphous alloys catalysts on supporters with different specific surface areas were prepared by the impregnation-reduction method.Used in hydroformylation of 1-hexene,the conversion of 1-hexene was above 92%,the heptanal selectivity was higher than 90%.The supported Ni-Co-B showed enhanced activity than Ni-Co-B,suggesting the promoting effect of the supporter due to the dispersion of the Co active sites.The catalytic activity was in order:Ni-Co-B/SBA-15>Ni-Co-B/AC?Ni-Co-B/MCM-41>Ni-Co-B/ZSM-5.Using AC supporter,the catalysts with varied Co loadings,and varied particle sizes of AC were prepared.With Co loading of 16.7%and the AC particle of 74-125 ?m,the catalyst showed the best catalytic activity.The conversion of 1-hexene,the yield of heptanal and the ratio of n-heptanal to isoheptanal was 95.9%,89.8%and 1.89,respectively.Appropriate conditions for Ni-Co-B/AC catalyzing hydroformylation of 1-hexene were H2/CO=1,5 MPa,120? and 3 h.The catalytic activity maintained 85%after reuse for 4 times,indicating the better stability of Ni-Co-B/AC.At the same condiotions the conversion for hydroformylation of 1-octene,1-decene and 1-dodecene,was above 88%and the selectivity of aldehydes was?90%.