Photochemical Solid-Phase Synthesis of Platinum Single Atoms on Nitrogen-Doped Carbon with High Loading as Bifunctional Catalysts for Hydrogen Evolution and Oxygen Reduction Reactions

Abstract

Currently, Pt single atoms as promising electrocatalysts have been applied to electrocatalysis aiming to significantly improve performance and remarkably lower usage of the noble metal. Herein, we propose a photochemical solid-phase reduction method to fabricate well-defined isolated Pt atoms on a nitrogen-doped porous carbon (Pt1/NPC). Using this simple and fast synthesis strategy, the formed Pt atoms are well-dispersed on the carbon without clusters or nanoparticles. The loading of the Pt is up to 3.8 wt % relative to the carbon. The Pt1/NPC catalyst displays an ultrahigh electrocatalytic activity for hydrogen evolution reaction with an overpotential of 25 mV at the current density of 10 mA cm–2 and mass activity of 2.86 A mg–1 Pt (24-times higher than a commercial Pt/C). Moreover, the catalyst also presents efficient catalytic activity for the oxygen reduction reaction. Its mass activity is 4.3-times that obtained by a commercial Pt (20 wt %). The improved electrocatalytic activities of the Pt1/NPC catalyst are ascribed to the favorable chemical and electronic structure of the Pt–N4 coordination raised by strong electron transfer from the isolated Pt atoms to the coordinated N atoms in this catalyst. The Pt1/NPC can be employed as a bifunctional catalyst for fuel cells and hydrogen production.

Engineering Local Coordination Environments of Atomically Dispersed and Heteroatom‐Coordinated Single Metal Site Electrocatalysts for Clean Energy‐Conversion

“…e) Schematic illustration of the formation of Pt SACs through adsorption of [PtCl 6 ] 2− and photoreduction. Reproduced with permission . Copyright 2018, American Chemical Society.…”

“…The [PtCl 6 ] 2− anions trapped in the micropores undergo dechlorination at 70 °C to form N‐coordinated Pt SACs. Also, a facile photochemical reduction method is effective to transform [PtCl 6 ] 2− anions adsorbed in N‐doped porous carbon into atomically dispersed and N‐coordinated Pt SACs (Figure e) . The final samples exhibited high electrocatalytic performance without requiring any post treatment.…”

Modulating the Electronic Structure of Single‐Atom Catalysts on 2D Nanomaterials for Enhanced Electrocatalytic Performance

“…Using a modified method with N‐doped graphene as support, Li et al successfully obtained the Pt SACs with high loading of 3.8 wt%. This method could be a scalable route to fabricate Pt single atoms on various support …”

Single Atoms on Graphene for Energy Storage and Conversion

“…Noble metals have been considered as one kind of the best‐performing catalysts for HER process due to their negligible overpotential and fast reaction rates . For instance, Ru atoms were successfully embedded on C 3 N 4 /rGO (Ru‐C 3 N 4 /rGO) by the simple thermal reduction ( Figure a).…”