| CMO is an important fine intermediate ,which is conventionally used as material in perfumey ,medicine and insecticide. The method of traditionally homogeneous chemical reduction is disadvantageous of high cost,difficult separation of products and environmental pollution, but heterogeneous catalystic technology can solve the problems. It is a challenge to hydrogenate on C=O in a molecule with C=C and C=O. The work is an important part of task, study on heterogeneous catalysts of selective hydrogenation of a,- unsaturated aldehyde to a - unsaturated alcohol supported by National Natural Science Foundation (No.20266001). The unnoble metal Cobalt catalysts were selected in the reaction system. The study was both of theoretical significance of selective hydrogenation and practical significance of making full of abound bay oil resources in GuangXi province.Cobalt-based catalysts of Co-La/Al2O3 modified by La and Co-Fe/Al2O3 modified by Fe were prepared by impregnation. The selectivity and activity of catalysts were elvaluated with active test. The technological conditions of preparation and reaction of catalysts were optimized. The effect of promoter on catalysts have been characterized by XPS, TPR, XRD, TG-DTG. Catalysts structure was related with the datum of activity and selectivty. Some regulations, the catalystic activity being affected with the change of structure, were revealed.After contrast of catalysts, it was found that over Co-La/Al2O3 modified by La the conversion of cinnamaldehyde was 17.78%, which was higher as 40.78% than that over Co/Al2O3, and the selectivity of cinnamayl alcohol was 89.18% under the conditions: PH, 2.0MPa; reaction temperature ,353K; the dosage of catalysts, 0.2g/ml(CMA); reaction time, 1 hour. Under the same reaction conditions the conversion of cinnamaldehyde was 14.78%, which was higher as 17.02% than that over Co/Al2O3,and the selectivity of cinnamayl alcohol was 94.37% over Co-Fe/Al2O3 modified by Fe. The study of catalysts preparation represented that with npromoter/nco being 0.08 and baking temperature being 823K the activity of catalysts showed the highest. The further study revealed that the introduction of Fe and La improved the reduction and dispersion drgree of active ingredient. The datumof I (Co2p)/I (A12p) of Co-La/Al2O3 in XPS changed from 2.231 without promoter to 2.76 and that of Co-Fe/Al2O3 changed from 2.231 without promoter to 3.82. The active ingredient also accumulated on the surface of catalysts, with content of Co increasing from 1.7% without promoter to 2.8% in Co-La/Al2O3 and increasing from 1.7% without promoter to 5.1% in Co-Fe/Al2O3. Thus the catalystic activities of catalysts were improved.Under the conditions: PH, 2.0MPa; reaction temperature, 353K, the optium dosage of catalysts of Co-La/Al2Os used in reaction was between 0.24g/ml(CMA) and 0.28g/ml(CMA) with the conversion of CMA being 59.83% and selectivity of CMO being 92.01% after having reacted for 3 hours. 5 hours later, the conversion and selectivity increased to 65.26% and 93.25% respectively. Under the same conditions the optium dosage of Co-Fe/Al2O3 was between 0.20g/ml(CMA) and 0.28g/ml(CMA), with the conversion of CMA being 30.47% and selectivity of CMO being 97.43% after having reacted for 3 hours. 5 hours later, the conversion was 60.51%, selectivity being 96.26%. That meaned that the hydrogenation over Co-Fe/Al2O3 had an incubation period with low activity at the earlier stage and gradually increased with the selectivity not change greatly. However the incubation period didn't happen in the hydrogenation over Co-La/ Al2O3, over which the conversion of CMA increased greatly at the earlier stage of 3 hours.With the reaction going on, the conversion increased slowly and the selectivity didn't change much.
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