Li Xiaoke, Paier Joachim
Institut für Chemie, Humboldt-Universität zu Berlin, Unter den Linden 6, 10099 Berlin, Germany.
J Chem Phys. 2020 Mar 14;152(10):104702. doi: 10.1063/1.5136323.
By virtue of density functional theory calculations, this work discusses several carbonate, carboxylate, and bicarbonate species on two thermodynamically relevant metal terminations of the (111) surface of magnetite, FeO. We present adsorption energies and vibrational wavenumbers and conclude in assigning the observed infrared reflection-absorption spectroscopy bands. CO prefers to adsorb molecularly on the Fe terminated FeO(111) surface, a finding consistent with observation. Calculations compared with the experiment lead to interpreting results in favor of the Fe (single metal) terminated FeO(111) surface as the regular surface termination. Formation of carbonate and bicarbonate requires metal impurities on that surface. Such impurities exist, for instance, on the Fe (double metal) termination, which can thus be used as a model for "metal-rich terminations" of more complex surfaces.
借助密度泛函理论计算，本研究探讨了磁铁矿（FeO）(111)表面两个热力学相关金属端面上的几种碳酸盐、羧酸盐和碳酸氢盐物种。我们给出了吸附能和振动波数，并通过对观测到的红外反射吸收光谱带进行了归属。CO更倾向于以分子形式吸附在Fe端的FeO(111)表面，这一发现与观测结果一致。将计算结果与实验结果进行比较，得出的解释结果支持Fe（单金属）端的FeO(111)表面为常规表面端面的观点。碳酸盐和碳酸氢盐的形成需要该表面存在金属杂质。例如，在Fe（双金属）端面上就存在这样的杂质，因此可以将其用作更复杂表面“富金属端面”的模型。
