Yates J L R, Spikes G H, Jones G
Department of Chemistry, University College London, 20 Gordon Street, London, WC1H OAJ, UK.
Phys Chem Chem Phys. 2015 Feb 14;17(6):4250-8. doi: 10.1039/c4cp04974h.
A selection of carbides (TiC, NbC, TaC, WC and SiC) have been studied using density functional theory. Their calculated adsorption characteristics towards Pt overlayers are presented with a view to the use of the carbides as core-shell components. WC hcp and SiC are observed to support Pt overlayers on all surfaces making them promising candidates for full Pt encapsulation. Pt adsorption on fcc (111) carbide surfaces is observed to take place with the transition metal surface resonances (TMSRs) playing a key role whilst fcc (100) are universally unfavourable towards Pt adsorption. The effect of the carbide supports on oxygen binding on the Pt overlayer is also considered and discussed in relation to the oxygen reduction reaction (ORR). The oxygen adsorption study revealed several Pt-WC surfaces which exhibit reduced oxygen adsorption energies, suggesting they should promote or maintain ORR activity with respect to nanoparticulate Pt catalysts.
已使用密度泛函理论研究了多种碳化物（碳化钛、碳化铌、碳化钽、碳化钨和碳化硅）。为了将这些碳化物用作核壳组件，展示了它们对铂覆盖层的计算吸附特性。观察到六方密排结构的碳化钨和碳化硅在所有表面上都能支撑铂覆盖层，这使它们成为完全铂封装的有前景的候选材料。观察到铂在面心立方（111）碳化物表面的吸附过程中，过渡金属表面共振（TMSR）起关键作用，而面心立方（100）表面普遍不利于铂的吸附。还考虑并讨论了碳化物载体对铂覆盖层上氧结合的影响与氧还原反应（ORR）的关系。氧吸附研究揭示了几个铂 - 碳化钨表面，其氧吸附能降低，表明相对于纳米颗粒铂催化剂，它们应促进或保持ORR活性。
