Abstract：
Noble metal nanocrystals face challenges in effectively catalyzing electrochemical ethanol oxidation reaction (EOR)-represented multistep, multielectron transfer processes due to the linear scaling relationship among binding energies of intermediates, impeding independent optimization of individual elemental steps. Herein, we develop noble metal nanocrystals with a range of local surface binding affinities in close proximity to overcome this challenge. Experimentally, this is demonstrated by applying tensile strain to a Pd surface and decorating it with discrete Au atoms, forming a diversity of binding sites with varying affinities in close proximity for guest molecules, as evidenced by CO probing and density functional theory calculations. Such a surface enables reaction intermediates to migrate between different binding sites as needed for each elemental step, thereby reducing the energy barrier for the overall EOR when compared to reactions at a single site. On these tailored surfaces, we attain specific and mass activities of 32.7 mA cm-2 and 47.8 A mgPd-1 in EOR, surpassing commercial Pd/C by 10.9 and 43.8 times, respectively, and outperforming state-of-the-art Pd-based catalysts. These results highlight the promise of this approach in improving a variety of multistep, multielectron transfer reactions, which are crucial for energy conversion applications.
摘要：
贵金属纳米晶体在有效催化以电化学乙醇氧化反应（EOR）为代表的多步反应方面面临挑战，由于中间体结合能之间的线性比例关系，多电子转移过程，阻碍各个元素步骤的独立优化。在这里，我们开发的贵金属纳米晶体具有一系列的局部表面结合亲和力，以克服这一挑战。实验上,这通过对Pd表面施加拉伸应变并用离散的Au原子装饰来证明，在客体分子附近形成具有不同亲和力的多种结合位点，CO探测和密度泛函理论计算证明了这一点。这种表面使反应中间体能够根据每个元素步骤的需要在不同的结合位点之间迁移。从而当与单个位点处的反应相比时,降低了总EOR的能量势垒。在这些量身定制的表面上，我们在EOR中获得了32.7mAcm-2和47.8AmgPd-1的比和质量活性，分别超过商用Pd/C10.9倍和43.8倍，分别,和优于现有技术的Pd基催化剂。这些结果突出了这种方法在改进各种多步骤，多电子转移反应，这对能量转换应用至关重要。
