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采用密度泛函理论(DFT)以及广义梯度近似方法(GGA)计算了甲酸根(HCOO)在Cu(110)、Ag(110)和Au(110)表面的吸附.计算结果表明,短桥位是最稳定的吸附位置,计算的几何参数与以前的实验和计算结果吻合.吸附热顺序为Cu(110)(-116kJ·mol-1)>Ag(110)(-57kJ·mol-1)>Au(110)(-27kJ·mol-1),与实验上甲酸根的分解温度相一致.电子态密度分析表明,吸附热顺序可以用吸附分子与金属d-带之间的Pauli排斥来关联,即排斥作用越大,吸附越弱.另外还从计算的吸附热数据以及实验上HCOO的分解温度估算了反应CO2+1/2H2→HCOO的活化能,其大小顺序为Au(110)>Ag(110)>Cu(110).
Adsorption of formate (HCOO) on Cu (110), Ag (110) and Au (110) surfaces was calculated by using density functional theory (DFT) and generalized gradient approximation (GGA) The most stable adsorption sites and the calculated geometrical parameters agree well with those of previous experiments and calculations.The order of adsorption heat is Cu (110) (-116 kJ · mol-1)> Ag (110) (-57 kJ · mol-1)> Au (110) (-27 kJ · mol-1), consistent with the experimental decomposition temperature of formate.The electronic density of states analysis shows that the order of adsorption heat can be related by the Pauli exclusion between the adsorbed molecules and the metal d-band, that is The larger the repulsive action, the weaker the adsorption.The activation energy of the reaction CO2 + 1 / 2H2 → HCOO was also estimated from the calculated adsorption heat data and experimental HCOO decomposition temperature in the order of Au (110)> Ag (110) )> Cu (110).