In this study, we loaded Pd catalysts onto a reduced graphene oxide (rGO) support in an atomically dispersed fashion [i.e., Pd single-atom catalysts (SACs) on rGO or Pd₁/rGO] via a facile and scalable synthesis based on anchor-site and photoreduction techniques. The as-synthesized Pd₁/rGO significantly outperformed the Pd nanoparticle (Pd_nano) counterparts in the electrocatalytic hydrodechlorination of chlorinated phenols. Downsizing Pd_nano to Pd₁ leads to a substantially higher Pd atomic efficiency (14 times that of Pd_nano), remarkably reducing the cost for practical applications. The unique single-atom architecture of Pd₁ additionally affects the desorption energy of the intermediate, suppressing the catalyst poisoning by Cl^–, which is a prevalent challenge with Pd_nano. Characterization and experimental results demonstrate that the superior performance of Pd₁/rGO originates from (1) enhanced interfacial electron transfer through Pd–O bonds due to the electronic metal–support interaction and (2) increased atomic H (H*) utilization efficiency by inhibiting H₂ evolution on Pd₁. This work presents an important example of how the unique geometric and electronic structure of SACs can tune their catalytic performance toward beneficial use in environmental remediation applications.

中文翻译：

---

阐明单原子 Pd 在电催化加氢脱氯中的作用

在这项研究中，我们通过基于锚定的简便且可扩展的合成，以原子分散的方式将 Pd 催化剂负载到还原氧化石墨烯 (rGO) 载体上 [即，rGO 或 Pd ₁ /rGO上的 Pd 单原子催化剂 (SAC) ] -现场和光还原技术。在氯化酚的电催化加氢脱氯中，合成的 Pd ₁ /rGO 显着优于 Pd 纳米颗粒 (Pd _nano ) 对应物。将 Pd _nano缩小为 Pd ₁可显着提高 Pd 原子效率（是 Pd _{nano 的}14 倍），显着降低了实际应用的成本。Pd ₁独特的单原子结构此外，还会影响中间体的解吸能，抑制 Cl ^-对催化剂的中毒，这是 Pd _nano的普遍挑战。表征和实验结果表明，Pd ₁ /rGO的优异性能源于（1）由于电子金属 - 载体相互作用而通过 Pd-O 键增强界面电子转移和（2）通过以下方式提高原子 H（H*）利用效率抑制Pd ₁上的H ₂演化。这项工作提供了一个重要的例子，说明 SACs 独特的几何和电子结构如何调整其催化性能，使其在环境修复应用中发挥有益作用。