钒酸盐络合剂对V2O5/TiO2 SCR催化剂织构和催化性能的影响

以商业锐钛矿型TiO₂为载体，通过浸渍法制备了3种不同钒酸盐络合剂的V₂O₅/TiO₂催化剂，并考察不同钒酸盐络合剂对该3种催化剂SCR反应的影响。对前驱体溶液的钒配合物价态、pH值，以及对催化剂样品进行H₂-TPR、BET比表面积和孔结构特征、NH₃-TPD、XRD、拉曼光谱、紫外等表征。研究发现，不同络合剂会影响钒酸盐在前驱体溶液中的价态，同时影响前驱体溶液的pH值，但是在测试温度范围内，该3种催化剂的SCR反应在活性和N₂选择性均无明显区别。通过不同的表征方法可知:催化剂的比表面积、孔结构、表面钒氧化物的聚合程度、H₂反应活化能、催化剂表面酸量均没有明显区别，前驱体溶液中钒配合物的价态和pH值对催化剂样品的SCR反应催化性能没有明显影响。

EFFECTS OF CHELATING AGENTS OF VANADIUM SALT ON PHYSICOCHEMICAL PROPERTIES AND CATALYTIC PERFORMANCES OF V2O5/TiO2 SCR CATALYST

Based on commercial anatase TiO₂, three catalysts were prepared using different chelating agents of vanadium salt by wet impregnation, and then studied the catalytic performances of SCR. Characterizing measures including H₂-TPR, N₂ adsorption-desorption with BET method, NH₃-TPD, XRD, Raman, and UV-Vis DRS were conducted to investigate the physicochemical properties of V₂O₅/TiO₂ catalysts. It was found that the diverse chelating agents of vanadium salt had great impact on the valence states of vanadium and pH value of precursor solution. Nonetheless, within the test temperature ranges, there were no distinction on the SCR activity and N₂ selectivity. By means of disparate characterization methods, it was concluded that there was almost no difference among those three catalysts on specific surface area, pore structure, polymerization degree of vanadium oxides on the surface of TiO₂, H₂ activation energy and surface acidity. Meanwhile, the valence states of vanadium and pH value of precursor solution could not affect the catalytic performances of V₂O₅/TiO₂ SCR catalysts.