Modulating the d‐Band Center Enables Ultrafine Pt₃Fe Alloy Nanoparticles for pH‐Universal Hydrogen Evolution Reaction

Abstract

By providing dual active sites to synergistically accelerate the H2O 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 Pt3Fe alloys (Pt3Fe/NMCS‐A) as a highly‐efficient electrocatalyst for pH‐universal HER is reported. The Pt3Fe/NMCS‐A exhibits low overpotential (η10) of 13, 29, and 48 mV to deliver 10 mA cm−2 in 0.5 M H2SO4, 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 Pt3Fe/NMCS‐A to dissociate the H2O to afford H* intermediates, which greatly promotes the H* intermediates adsorption and H2 formation in alkaline and neutral conditions. The synthetic strategy is further extended to the synthesis of Pt3Co and Pt3Ni 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

Intermetallic Nanocrystals for Fuel-Cells-Based Electrocatalysis

“…Introducing oxyphilic elements to either adjust the electronic structures of active Pt/Pd hosts through ligand/ strain effect, or alleviate their poisoning via synergistic/ bifunctional mechanism, has been widely recognized as effective strategy to promote currently applied Pt-/Pd-based AOR/FAOR/HOR electrocatalysts. 27,778,779 As discussed above for ORR, intermetallic materials enjoy intensified ligand/strain effect and thereby elevated capacity to optimize d-band structure so as to provide more appropriate adsorption strength of key intermediates, which not only determines the reaction kinetics, but also has great influence on the pathway selectivity. More advanced, in the ideal intermetallics system, all the Pt/Pd active sites get fully diluted or even totally isolated due to the alternated atomic arrangement, which contributes to dramatical weakening of toxic species and therefore endows intermetallic anodic catalysts with superior Despite of the as-demonstrated advantages, additional promotion strategies are still demanded to further optimize the electronic structure to precisely tune the adsorption energy of multiple intermediates as well as to prevent the alloying element from excessive leaching.…”

Optimizing Pt-Based Alloy Electrocatalysts for Improved Hydrogen Evolution Performance in Alkaline Electrolytes: A Comprehensive Review

“…154,155 The downshift of the dband center reduces the adsorption energy of the H intermediate and promotes the desorption of hydrogen from the catalyst surface. 156,157 Strain can also reduce the band gap and improve the conductivity up to the point to trigger a semiconductor-to-metal transition. 158 A particular case of HER catalysts where bond length is especially important is that of single-atom alloy catalysts.…”

“…The strain causes the d-band center of the catalyst to shift with respect to the Fermi level. Specifically, the upshift of the d-band center will change the overlap with the hydrogen σ* orbital and the strength of the metal–H bond, thereby regulating the adsorption and desorption of the adsorbate. , The downshift of the d-band center reduces the adsorption energy of the H intermediate and promotes the desorption of hydrogen from the catalyst surface. , Strain can also reduce the band gap and improve the conductivity up to the point to trigger a semiconductor-to-metal transition …”

Confinement engineering for enhanced electrocatalytic nitrate reduction by integrating B-doped graphene with iron catalysts for long-term stability

“…It is well established that noble metal catalysts such as Pt, Pd, and Ru exhibit better catalytic efficiency; however, limited precious metal resources increase the catalyst cost, and these are not conducive to long-term industrial-scale development. 11–13 Recently, transition-metal catalysts have shown great potential in various catalytic fields. 14–16 Among them, Fe-based catalysts have attracted considerable attention owing to their advantages such as wide availability and good environmental compatibility.…”