395 / 2018-12-20 13:29:30

Experimental Study on Photocatalytic Reduction of Carbon Dioxide to Methanol

Carbon dioxide; Photocatalyst; Titanium dioxide; Methanol

全体主题 > 替代能源

In this paper, modified sol-gel method was used to prepare TiO2 modified by Cu and La at different temperatures. XRD, BET, SEM, TG/DSC and other methods were used to analyze the physicochemical properties, and the catalyst performance test was carried out.
The results show that the calcination temperature mainly affects the crystal form of TiO2: when the calcination temperature does not exceed 500 °C, TiO2 mainly exists in the anatase crystal form; 600 °C is the crystal phase transition temperature of TiO2 from anatase to rutile, when anatase only accounts for about 38%, the rest are rutile; at 700 °C, TiO2 is all converted to rutile, which has strong thermal stability; TiO2 obtained by calcining at 400 °C has low crystallinity and contains more amorphous TiO2. The 2wt.% Cu/TiO2 prepared after calcining at 500 °C has the best surface properties in the experimental range, the grain size is 17.03 nm, the specific surface area is 49.084 m2/g, and its 95.7% pores have a pore size distribution between 2 and 20 nm, which is a good mesoporous material.
The photocatalytic reaction was carried out using the prepared TiO2 catalyst. It was found that the highest yield of methanol is obtained by using the TiO2 catalyst prepared by calcining at 500°C, the catalytic activity of anatase was much higher than that of rutile, and amorphous TiO2 does not have catalytic activity. The reaction temperature has a great influence on the catalytic activity. When the temperature is increased from 20 °C to 90 °C, the methanol yield can be doubled for every 15 °C increase.