Cu-Ni/ZrSiO催化剂的制备及其对CO_2和CH_3OH合成DMC的反应性能

采用表面反应改性法制备了ZrO2 SiO2 (ZrSiO)复合载体 ,以等体积浸渍法制备了ZrSiO担载的Cu Ni及Cu Ni K2 O催化剂。用IR、TPSR MS和MRS 90 1微反技术考察了CO2 和CH3OH在催化剂上的化学吸附和反应性能。结果表明 ,CO2 在金属位 (M )和Lewis酸位Zrn + 的协同作用下形成卧式吸附态M CO O→Zrn + ,CH3OH在Zrn + 和Zr O 两类中心的协同作用下形成解离吸附态Zr OCH3 和Zr OH ;在适宜的反应条件 (温度 140℃、压力 0 6MPa、空速 144 0h 1、n(CH3OH) /n(CO2 ) =2下 ,反应的总碳转化率可达 8% ,生成DMC的选择性大于 87% ;适量引入助剂K2 O可明显提高DMC的收率

Preparation of Cu-Ni/ZrO_2-SiO_2 catalyst and its reactivity for dimethyl carbonate direct synthesis from CO_2 and CH_3OH

The surface complex oxide support ZrO 2 SiO 2 (ZrSiO) was prepared by surface reaction modification.Cu Ni/ZrSiO and Cu Ni K 2O/ZrSiO catalyst were prepared by the incipient wetness technique.Chemisorption and reactivity of CO 2 with CH 3OH on the catalysts were characterized by IR,TPSRMS and microreactor techniques.The results showed that CO 2 horizontal adsorption state (M CO O→Zr n+ )can be formed on the metal site(M) in cooperation with Lewis acide site(Zr n+ ),and CH 3OH can be dissociated into Zr OCH 3 and Zr OH with the cooperation of Zr n+ and adjacent Zr O sites.Under the reaction conditions of temperature 140℃,pressure 0 6MPa,space velocity 1440h 1 ,CH 3OH/CO 2=2(mol ratio),the conversion of total carbon number in CO 2 and CH 3OH reached 8%,and the selectivity of dimethyl carbonate(DMC) was over 87%.The yield of DMC can be improved by adding K 2O to the Cu Ni/ZrSiO catalyst.