Synergistic electronic-geometric regulation of Pt-based intermetallics resolves the activity-selectivity trade-off in borohydride oxidation.

Jiang, Wenxing; Liu, Yong; Wan, Qiqi; Zhang, Endao; Shen, Xiaodong; Jiang, Kaiyue; Zhuang, Xiaodong; Ke, Changchun · Nat Commun · 2026

basic_science · Level V

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Abstract

Direct borohydride fuel cells (DBFCs) exhibit a high theoretical energy density of 9946 Wh L<sup>-1</sup>, yet their application is hindered by the competition between the target 8-electron borohydride oxidation reaction (8e-BOR) and the parasitic incomplete borohydride oxidation reaction (i-BOR). Herein, we resolve this activity-selectivity trade-off by synergistically regulating the electronic and geometric structures of ordered Pt-based intermetallic catalysts (IMCs). Pt-Fe orbital coupling lowers the d-band center by 0.37 eV, weakening the adsorption of intermediates that trigger i-BOR. Meanwhile, the ordered lattice isolates Pt sites, disrupting the continuous Pt-Pt ensembles required for i-BOR. This dual regulation effectively suppresses hydrogen evolution, yielding a near-ideal electron transfer number of 7.72. A DBFC using a Pt-Fe IMC anode delivers a peak power density of 1208 mW cm<sup>-2</sup> with 60.3% fuel utilization. Scalability is further demonstrated through a 1.3 kW industrial stack, confirming its practical potential. This work provides a general strategy for managing selectivity in complex electrocatalytic systems.