氮化碳对Cu-ZnO-Al_(2)O_(3)催化CO_(2)加氢合成甲醇的影响

Effect of Carbon Nitride Addition on Cu-ZnO-Al_(2)O_(3) Catalytic Performance for CO_(2)Hydrogenation to Methanol

采用固体混合法制备了石墨相氮化碳(g-C 3N 4)复合Cu-ZnO-Al 2O 3催化剂,通过XRD、H 2-TPR、CO 2-TPD和N 2O滴定等表征手段对催化剂进行表征,并将其用于CO 2加氢合成甲醇反应。结果表明,g-C 3N 4的适量添加可以提高催化剂上铜物种的分散度和催化剂的碱性位点,增加铜颗粒的比表面积,有利于CO 2的吸附及活化,当添加5%质量分数的氮化碳时,催化剂催化效果显著提高,在200℃、3.0 MPa的反应条件下,CO 2转化率达到7.6%,甲醇选择性为74.4%。

Graphite phase carbon nitride(g-C 3N 4)composite Cu-ZnO-Al 2O 3 catalyst was prepared by solid mixing method and it was used as the catalyst for CO 2 hydrogenation to methanol reaction.The prepared catalyst was characterized with X-Ray Diffraction(XRD),H 2-Temperature Programmed Reduction(H 2-TPR),CO 2-Temperature Programmed Desorption(CO 2-TPD),and N 2O titration.Experimental results showed that addition of appropriate amount of g-C 3N 4 can increase the base sites of the catalyst and the specific surface area of the metal copper,and also can improve copper dispersion in the catalyst.All of the above can improve CO 2 adsorption and activation capability.With addition of 5%mass fraction carbon nitrides,the prepared composite catalyst performance can be significantly improved.Under reaction conditions of 200℃and 3.0 MPa,carbon dioxide conversion ratio and methanol selectivity can be 7.6%and 74.4%,respectively.