关键词: 分离, 回收, 催化, 甲醛乙炔化, 1, 4-丁炔二醇, 磁性

Abstract:

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.

Key words: separation, recovery, catalysis, formaldehyde ethynylation, 1,4-butynediol, magnetic