镍基双金属催化剂上甲烷脱氢反应的密度泛函理论

Density Functional Theory Study of Methane Dehydrogenation on Ni-based Bimetallic Surfaces

为了从原子尺度上研究双金属的作用机理,采用基于密度泛函理论的第一性原理方法研究了甲烷在Ni-Pt和Ni-Pd双金属催化剂上的脱氢过程。计算结果表明,在Ni催化剂中引入Pt或Pd会大大减弱表面C原子的吸附,从而提高催化剂的抗积炭能力,而且甲烷第一步脱氢活化能会有所提高,反应活性略有降低。

In order to gain insight of this process at atomic level, first-principles based on density functional theory was used to investigate methane dehydrogenation on Ni-Pt and Ni-Pd bimetallic surfaces. The calculation results showed that the introduction of Pt and Pd decreased the C adsorption energies on the bimetallic surfaces, which improved the coke resistance of the catalysts. Meanwhile, the activation energies for the first dehydrogenation step increased, indicating the decrease of the activity of the bimetallic catalysts.