Developing highly stable and active non-Pt oxygen reduction reaction (ORR) electrocatalysts for power generation device raises great concerns and remains a challenge. Here, we report novel truncated Pd tetrahedrons (T−Pd−Ths) enclosed by {111} facets with excellent uniformity, which have both low-coordinated surface sites and distinct lattice distortions that would induce “local strain”. In alkaline electrolyte, the T−Pd−Ths/C achieves remarkable ORR specific/mass activity (SA/MA) of 2.46 mA·cm⁻²/1.69 A·mg_Pd⁻¹, which is 12.3/16.9 and 10.7/14.1 times higher than commercial Pd/C and Pt/C, respectively. The T−Pd−Ths/C also exhibits high in-situ carbon monoxide (CO) tolerance and 50,000 cycles durability with an activity loss of 7.69% and morphological stability. The rotating ring-disk electrode (RRDE) measurements show that a 4-electron process occurs on T−Pd−Ths/C. Theoretical calculations demonstrate that the low-coordinated surface sites contribute largely to the enhancement of ORR activity. In actual direct methanol fuel cell (DMFC) device, the T−Pd−Ths/C delivers superior open-circuit voltage (OCV) and peak power density (PPD) to commercial Pt/C from 25 to 80 °C, and the maximum PPD can reach up to 163.7 mW·cm⁻². This study demonstrates that the T−Pd−Ths/C holds promise as alternatives to Pt for ORR in DMFC device.

开发用于发电装置的高度稳定和活性的非 Pt 氧还原反应 (ORR) 电催化剂引起了极大的关注，并且仍然是一个挑战。在这里，我们报告了由 {111} 晶面包围的新型截短 Pd 四面体（T-Pd-Ths），具有出色的均匀性，具有低配位的表面位点和会导致“局部应变”的明显晶格畸变。在碱性电解液中，T-Pd-Ths/C的ORR比/质量活性(SA/MA)为2.46 mA·cm ^-2 /1.69 A·mg _Pd ^-1，分别是12.3/16.9和10.7/14.1倍分别高于商业 Pd/C 和 Pt/C。T−Pd−Ths/C 也表现出高原位一氧化碳 (CO) 耐受性和 50,000 次循环耐久性，活性损失 7.69% 和形态稳定性。旋转环盘电极 (RRDE) 测量表明，在 T-Pd-Ths/C 上发生了 4 电子过程。理论计算表明，低配位表面位点很大程度上有助于提高 ORR 活性。在实际的直接甲醇燃料电池 (DMFC) 装置中，T−Pd−Ths/C 在 25 至 80 °C 范围内提供优于商用 Pt/C 的开路电压 (OCV) 和峰值功率密度 (PPD)，并且最大PPD最高可达163.7 mW·cm ^-2。这项研究表明，T-Pd-Ths/C 有望作为 Pt 的替代品用于 DMFC 设备中的 ORR。