Magnetic CuO-Bi2O3/Fe3O4-SiO2-MgO catalysts with different Cu content were prepared by using impregnation and coprecipitation methods. The obtained catalysts were characterized by atomic emission spectrometer (ICP-AES)

N2 absorption

X-ray diffraction (XRD)

H2 temperature-programmed reduction (H2-TPR) and vibrating sample magnetometer (VSM). Their catalytic performance for formaldehyde ethynylation was evaluated. The results indicated that preparation method showed a great influence on the CuO station in catalysts

thus

on the performance for formaldehyde ethynylation reaction. Compared with the catalysts prepared by impregnation

the CuO-Bi2O3/Fe3O4-SiO2-MgO catalysts prepared by co-precipitation method showed higher CuO dispersion and better reducibility

so had better catalytic activity and selectivity. Moreover

Cu content was another important factor affecting catalyst activity. With Cu content increasing

the catalyst activity increased gradually. In the present work

30% (mass) Cu loading catalyst prepared by co-precipitation method showed the highest catalytic activity. In addition

this catalyst was of good superparamagnetism and stability

so easy separated by external magnetic field for reuse. After six cycles

its stability was much better than non-paramagnetism CuO-Bi2O3/SiO2-MgO catalyst.