掺杂改性对钙铝基复合物酯交换催化剂吸附性能影响的分子模拟

Molecular simulation of the effect of doping modification on the adsorption properties of calcium-aluminum-based composites ester exchange catalysts

借助分子模拟手段,研究了锌、镧、镁掺杂改性对钙铝基复合型金属氧化物催化酯交换的影响。构建了Al2O3(110)、CaO(100)以及锌、镧、镁掺杂改性的衍生模型。计算了不同改性氧化铝表面的掺杂结合能,分析了甲醇和乙酸甲酯在氧化钙及其衍生物表面的吸附过程,讨论了甲醇在Al2O3(110)及其衍生物表面的吸附过程及其Mulliken电荷密度的变化。结果表明,采用锌、镧、镁掺杂改性能强化钙铝复合型金属氧化物催化剂对甲醇的吸附性能,有助于催化酯交换反应的进行。

With the help of molecular simulations,the effect of zinc,lanthanum and magnesium doping modification on the transesterification catalyzed by calcium-aluminum composite catalyst was studied.The model for Al2O3(110)and CaO(100)surfaces were constructed and a series of derivative models doped by zinc,lanthanum,and magnesium were then obtained.Doping binding energy of various doped Al2O3(110)surfaces were calculated.The adsorption process of methanol and methyl acetate on CaO(100)and its derivative surfaces were analyzed.The adsorption process of methanol on Al2O3(110)and its derivative surfaces and the Mulliken charge density change were discussed.The results show that the calcium-aluminum composite catalysts doped with zinc,lanthanum,and magnesium can enhance the adsorption performance for methanol,which contribute a lot to catalyzing transesterification reaction.