Preparation of CuO-Bi2O3/SiO2@TiO2 core-shell structured catalysts and its catalytic performance for synthesis of 1, 4-butynediol by ethynylation of formaldehyde

CuO-Bi2O3/SiO2@TiO2 core-shell structured catalysts were prepared by stepwise precipitation method and used for the synthesis of 1, 4-butynediol (BYD) by the ethynylation of formaldehyde. The characterization results, by XRD, BET, SEM, TEM, TPD etc., revealed the TiO2 content not only affecting the surface area of the catalysts and the grain size of the loaded CuO, but also affecting the electronic interactions with CuO. The activity tests showed that the catalyst with 20% TiO2 calcined at 450 °C had a short activation time, with good activity with conversion 91% and BYD yield 73% after 6 h on line. The catalysts still maintained good catalytic activity and stability after 6 repeated uses. ICP data indicate that leaching of Cu active component after reaction is very low.