PtML/WC（0001）表面CO和CH3OH吸附的密度泛函理论研究

A density functional theory study on CO and CH3OH adsorption on PtML/WC（0001） surface

利用密度泛函理论和周期平板模型建立并计算了Pt(111)/WC(0001)界面原子模型,得到了单层Pt(111)在WC(0001)表面Hcp位结合的PtML/WC(0001)表面模型。对PtML/WC(0001)表面的结合能、态密度和电荷密度的计算结果进行分析,发现在界面处有电荷累积,表明形成了W-Pt金属键。计算了CO和CH3OH在PtML/WC(0001)和Pt(111)表面最稳定吸附位的吸附能、态密度和Mulliken电荷数,结果表明:与在Pt(111)表面相对比,CO和CH3OH分子在PtML/WC(0001)表面吸附较弱,证明Pt/WC催化剂在理论上能够较好地催化甲醇,比Pt/C催化剂具有较高的抗CO中毒能力。

A atomistic interface model for Pt(111)/WC(0001),a Pt(111)monolayer depositing on the Hcp sites of a WC(0001)surface,was constructed by using the density functional theory and self-consistent periodic slab mode.The binding energy,density of states,and charge density were calculated and analyzed.The results show that electrical charges accumulate at the interface,indicating that the strong Pt-W metal bonds form between the W and Pt atoms.The adsorption energy,density of states,and Mulliken population of CO and CH3OH on the PtML/WC(0001)surface were also calculated and compared with the corresponding values on the Pt(111)surface.The results show that the adsorption energy of CO and CH3OH on the PtML/WC(0001)surface are weaker than that on the Pt(111)surface.The Pt/WC catalyst shows a higher catalytic activity for methanol oxidation reaction and a higher resistance to CO poisoning than does the Pt/C catalyst.