Weakening O‑Intermediates Adsorption Strength\nOver the Pd Metallene via Lewis-Acidic Site Modulation for Enhanced\nOxygen Reduction

The\nreasonable design and modulation of the electronic properties\nof Pd metallene are acknowledged as a promising avenue for enhancing\nthe oxygen reduction reaction (ORR) in anion exchange membrane fuel\ncells (AEMFCs), yet they remain a formidable challenge. Herein, a\nthin-sheet structure of Zr-doped Pd metallene (PdZr metallene) with\nabundant defects is proposed using a facile wet-chemical approach\nfor efficient and highly durable ORR electrocatalysis. Multiple microstructural\nanalyses uncover that orchestrated electronic and oxophilic regulation\nof PdZr metallene via Lewis-acidic Zr site modulation could concurrently\noptimize the electronic configuration of Pd, downshift the d-band\ncenter of Pd, and, thus, promote the intrinsic activity. Benefiting\nfrom the unique two-dimensional morphology and electronic structure\noptimization facilitated by the Zr coupling effect, the resultant\nPdZr metallene demonstrates significantly enhanced ORR electrocatalytic\nperformance in basic solutions, with a high half-wave potential (<i>E</i><sub>1/2</sub>) of 0.87 V and commendable stability for\n30 000 s, surpassing those of Pd metallene and various advanced\nPd-based catalysts reported in the literature. Encouragingly, the\nPdZr metallene-based AEMFC achieves an increased maximum power density\n(90.4 mW cm<sup>–2</sup>) and impressive robustness over 12\nh in an alkaline environment, manifesting the practical application\nof PdZr metallene in AEMFCs. This study showcases the applicability\nof PdZr metallene via Lewis acid site regulation for fabricating highly\nactive electrocatalysts for high-performance AEMFCs.