固载量对固载化磷钨酸结构性能及催化CO_(2)和甲醇合成碳酸二甲酯的影响

Effect of the Loading Amounts on Structural Properties of Immobilized Phosphotungstic Acid and Catalysis for Synthesis of Dimethyl Carbonate from CO_(2) and Methanol

本文研究了氨基硅烷改性硅胶负载的磷钨酸催化CO_(2)和甲醇直接合成碳酸二甲酯(Dimethyl Carbonate,DMC)的催化活性,并采用X射线衍射仪(XRD)、物理吸附仪(BET)、同步热分析仪(TG)、CO_(2)/NH_(3)-程序升温脱附(CO_(2)/NH_(3)-TPD)表征催化剂结构。结果表明,随着载体量的增加,DMC的收率先降低后增加,在固载比例为1∶1时DMC的收率最高,为0.1519 mmol/g。该催化剂属于三斜晶系,稳定性较好,酸碱性位点最多,比表面积为1.4056 m^(2)/g,孔体积为0.000523 cm^(3)/g。

The catalytic activity of phosphotungstic acid supported on silica gel modified by aminosilane for direct synthesis of DMC from CO_(2) and methanol is studied.The structure of catalysts is characterized by XRD,BET,TG and CO_(2)/NH_(3)-TPD.The results show that with the increase of the amount of support,the yield of DMC first decreased and then increased.When the support ratio is 1∶1,the yield of DMC is the highest,which is 0.1519 mmol/g.The catalyst belongs to triclinic system,has good stability and most acid and base sites.Moreover,it has a specific surface area of 1.4056 m^(2)/g and a pore volume of 0.000523 cm^(3)/g.