Modulating The D-Band Center Enables Ultrafine Pt 3 Fe Alloy Nanoparticles for Ph-Universal Hydrogen Evolution Reaction.

By providing dual active sites to synergistically accelerate the H 2 O dissociation and H + reduction, ordered intermetallic alloys usually show extraordinary performance for pH-universal hydrogen evolution reaction (HER). Herein, activated N-doped mesoporous carbon spheres-supported intermetallic Pt 3 Fe alloys (Pt 3 Fe/NMCS-A) as a highly-efficient electrocatalyst for pH-universal HER is reported. The Pt 3 Fe/NMCS-A exhibits low overpotential (η 10 ) of 13, 29, and 48 mV to deliver 10 mA cm -2 in 0.5 M H 2 SO 4 , 1.0 M KOH, and 1.0 M phosphate buffered solution (PBS), respectively, as well as robust stability to maintain the overall catalytic performances. Theoretical studies reveal that the strong Pt 5d-Fe 3d orbital electronic interactions negatively shift the d-band center of Pt 5d orbital, resulting in reduced H* adsorption energy of Pt sites and enhanced acidic HER activity. With Pt and Fe acting as co-adsorption sites for H* and *OH intermediates, respectively, a low energy barrier is required for Pt 3 Fe/NMCS-A to dissociate the H 2 O to afford H* intermediates, which greatly promotes the H* intermediates adsorption and H 2 formation in alkaline and neutral conditions. The synthetic strategy is further extended to the synthesis of Pt 3 Co and Pt 3 Ni alloys with excellent HER activity in pH-universal electrolytes, demonstrating the great potential of these Pt-based alloys for practical applications. This article is protected by copyright. All rights reserved.