Haile Asnake Sahele, Yohannes Weldegebriel, Mekonnen Yedilfana Setarge
Center for Environmental Science, College of Natural and Computational Sciences, Addis Ababa University P.O. Box 1176 Addis Ababa Ethiopia
Chemistry Department, College of Natural and Computational Sciences, Addis Ababa University P.O. Box 1176 Addis Ababa Ethiopia.
RSC Adv. 2020 Jul 21;10(46):27346-27356. doi: 10.1039/d0ra02972f.
Pt-non-precious transition metals (Pt-NPTMs) alloy electrocatalysts have gained considerable attention to develop cheaper and efficient electrocatalysts for oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs). In this report, density functional theory (DFT) has been applied to study the catalytic activity of Pt-skin PtV(111) electrocatalyst for ORR in PEMFCs. The results revealed that the ORR intermediates (O, OH and OOH) have lower binding energies on Pt-skin PtV(111) compared to pure Pt(111) surface. The ORR on Pt-skin PtV(111) surface proceed OOH dissociation with an activation energy of 0.33 eV. The formation of OH is found to be the rate determining step with an activation energy of 0.64 eV, which is even lower than in pure Pt(111) surface (0.72 eV). This indicates a better performance of Pt-skin PtV(111) for ORR compared to pure Pt(111) surface. Moreover, the DFT results revealed that the negative formation energy of the PtV alloy and the positive dissolution potential shift of the surface Pt atoms revealed the better stability of Pt-skin PtV(111) surface over pristine Pt(111) surface. Due to the improved activity and better stability, the new PtV alloy electrocatalyst is very promising for the development of low-cost and efficient PEMFCs.
铂-非贵金属过渡金属（Pt-NPTMs）合金电催化剂在开发用于质子交换膜燃料电池（PEMFCs）中氧还原反应（ORR）的更便宜且高效的电催化剂方面受到了广泛关注。在本报告中，密度泛函理论（DFT）已被用于研究Pt-表层PtV(111)电催化剂对PEMFCs中ORR的催化活性。结果表明，与纯Pt(111)表面相比，ORR中间体（O、OH和OOH）在Pt-表层PtV(111)上具有更低的结合能。Pt-表层PtV(111)表面上的ORR以0.33 eV的活化能进行OOH解离。发现OH的形成是速率决定步骤，其活化能为0.64 eV，甚至低于纯Pt(111)表面（0.72 eV）。这表明与纯Pt(111)表面相比，Pt-表层PtV(111)对ORR具有更好的性能。此外，DFT结果表明，PtV合金的负形成能和表面Pt原子的正溶解电位偏移表明Pt-表层PtV(111)表面比原始Pt(111)表面具有更好的稳定性。由于活性的提高和更好的稳定性，新型PtV合金电催化剂在开发低成本且高效的PEMFCs方面非常有前景。
