Pd-based core-shell alloy-supported catalysts were prepared sequentially via a microwave-assisted polyol method and galvanic replacement. To investigate the effect of the core composition on the catalytic activity of such catalysts, three different Pd alloy cores (PdNi, PdCu, and PdNiCu) were prepared on carbon supports using a polyol method. Then, Pd and Ir were introduced simultaneously to form shells on the Pd alloy cores by galvanic replacement in aqueous solution, thereby producing catalysts designated as [email protected]/C, [email protected]/C, and [email protected]/C. X-ray diffraction revealed that all three catalysts exhibited the face-centered cubic structure of Pd without the presence of individual phases for Ni, Cu, and Ir. The core-shell structure of the Pd-based alloy nanoparticles on the carbon support was verified by the electron energy loss spectroscopy line profile of a 25 nm nanoparticle of [email protected]/C. Among the three Pd-based core-shell catalysts, the highest electrochemical surface area and oxygen reduction reaction (ORR) activity was observed for [email protected]/C. In addition, the membrane electrode assembly employing the [email protected]/C catalyst displayed a significantly improved voltage compared to the other two catalysts under high-temperature polymer electrolyte membrane fuel cell conditions at 150 °C. Single-cell durability tests conducted to measure the voltage change at a constant current density of 0.2 A cm⁻² showed a decay ratio of 12.3 μV h⁻¹. These results suggest that the composition of the core in core-shell nanoparticles has an important influence on both the electronic properties in the Pd alloy core and compressive lattice strain on the PdIr shell. Control of these synergistic effects provides a new approach for developing catalysts with high ORR activity.

通过微波辅助多元醇法和电流置换法依次制备了钯基核壳合金负载的催化剂。为了研究核组成对此类催化剂催化活性的影响，使用多元醇方法在碳载体上制备了三种不同的Pd合金核（PdNi，PdCu和PdNiCu）。然后，同时引入Pd和Ir，以通过在水溶液中进行电置换而在Pd合金芯上形成壳，从而产生命名为[电子邮件保护] / C，[电子邮件保护] / C和[电子邮件保护] / C的催化剂。X射线衍射表明，所有三种催化剂均表现出Pd的面心立方结构，而Ni，Cu和Ir没有单独的相。通过[电子邮件保护] / C的25 nm纳米颗粒的电子能量损失谱线轮廓验证了碳载体上Pd基合金纳米颗粒的核-壳结构。在三种基于Pd的核壳催化剂中，[电子邮件保护] / C的电化学表面积和氧还原反应（ORR）活性最高。此外，在150℃的高温聚合物电解质膜燃料电池条件下，与其他两种催化剂相比，采用[电子邮件保护] / C催化剂的膜电极组件显示出显着改善的电压。进行单电池耐久性测试，以在0.2 A cm的恒定电流密度下测量电压变化 在三种基于Pd的核壳催化剂中，[电子邮件保护] / C的电化学表面积和氧还原反应（ORR）活性最高。此外，在150℃的高温聚合物电解质膜燃料电池条件下，与其他两种催化剂相比，采用[电子邮件保护] / C催化剂的膜电极组件显示出显着改善的电压。进行单电池耐久性测试，以在0.2 A cm的恒定电流密度下测量电压变化 在三种基于Pd的核壳催化剂中，[电子邮件保护] / C的电化学表面积和氧还原反应（ORR）活性最高。此外，在150℃的高温聚合物电解质膜燃料电池条件下，与其他两种催化剂相比，采用[电子邮件保护] / C催化剂的膜电极组件显示出显着改善的电压。进行单电池耐久性测试，以在0.2 A cm的恒定电流密度下测量电压变化 与其他两种催化剂相比，在150°C的高温聚合物电解质膜燃料电池条件下，采用[电子邮件保护] / C催化剂的膜电极组件显示出显着改善的电压。进行单电池耐久性测试，以在0.2 A cm的恒定电流密度下测量电压变化 与其他两种催化剂相比，在150°C的高温聚合物电解质膜燃料电池条件下，采用[电子邮件保护] / C催化剂的膜电极组件显示出显着改善的电压。进行单电池耐久性测试，以在0.2 A cm的恒定电流密度下测量电压变化^-2的衰减率为12.3μVh ^-1。这些结果表明，核-壳纳米颗粒中核的组成对Pd合金核中的电子性能和PdIr壳上的压缩晶格应变都有重要影响。这些协同作用的控制为开发具有高ORR活性的催化剂提供了一种新方法。