A series of Cu2O/TiO2 catalysts were prepared by liquid reduction-deposition-precipitation technique from copper chloride as copper source

sodium hydroxide as precipitant

sodium L-ascrobate as reducer

and TiO2 calcined at different temperatures as support. The catalysts were characterized by X-ray diffraction (XRD)

H2-temperature programmed reduction (H2-TPR)

nitrogen physisorption

transmission electron microscopy (TEM)

and X-ray photoelectron spectroscopy (XPS). The catalytic activity of these catalysts were studied in formaldehyde ethynylation. The results showed that calcination temperature of TiO2 support had great influence on the catalytic activity of Cu2O/TiO2. TiO2 calcined at low temperature presented mainly as anatase phase and had weak interaction with Cu2O

which could cause over reduction of active Cu2O to inactive metal Cu and result in the decrease of catalytic activity. With the increase of calcination temperature

anatase TiO2 gradually transformed to rutile TiO2 which could inhibit over reduction of active Cu2O due to its strong interaction with Cu2O. As a result of efficient conversion of Cu2O to active Cu (I) ethynlate

the Cu2O/TiO2 catalyst with TiO2 support calcined at high temperatures had the best catalytic activity.