Unveiling the Nature of Pt Single‐Atom Catalyst during Electrocatalytic Hydrogen Evolution and Oxygen Reduction Reactions

Abstract

Single-atom catalysts (SACs) have attracted significant attention due to their superior catalytic activity and selectivity. However, the nature of active sites of SACs under realistic reaction conditions is ambiguous. In this work, high loading Pt single atoms on graphitic carbon nitride (g-C 3 N 4)-derived N-doped carbon nanosheets (Pt 1 /NCNS) is achieved through atomic layer deposition. Operando X-ray absorption spectroscopy (XAS) is performed on Pt single atoms and nanoparticles (NPs) in both the hydrogen evolution reaction (HER) and oxygen reduction reaction (ORR). The operando results indicate that the total unoccupied density of states of Pt 5d orbitals of Pt 1 atoms is higher than that of Pt NPs under HER condition, and that a stable Pt oxide is formed during ORR on Pt 1 /NCNS, which may suppress the adsorption and activation of O 2. This work unveils the nature of Pt single atoms under realistic HER and ORR conditions, providing a deeper understanding for designing advanced SACs.

A general strategy for preparing pyrrolic-N4 type single-atom catalysts via pre-located isolated atoms

“…2 ) and XAS results (Supplementary Fig. 3 ) 36 . The loading of Pt is as high as 2.0 wt% based on the inductively coupled plasma optical emission spectrometer (ICP-OES) results.…”

Graphene-based materials as electrocatalysts for the oxygen evolution reaction: a review

“…SACs consist of metal atoms individually fastened on a specific support, mostly doping-induced graphene materials. 97,98 The coordinating atom and the singly occupied metal sites create active centers for catalysis. The most attractive feature of SACs is their efficiency in the utilization of 100% of their metal centers to be active towards any catalytic application.…”

NH4F-Induced Morphology Control of CoP Nanostructures to Enhance the Hydrogen Evolution Reaction

“…It has been demonstrated that ideal electrocatalysts for the hydrogen evolution reaction (HER) are the Pt-group noble metals, which own the advantages of high intrinsic activity, low catalytic barrier, and excellent stability. However, the scarcity and expensive price limit their widespread applications. − Therefore, developing alternative electrocatalysts with outstanding HER catalytic performance and abundant reserve is quite desirable and indispensable.…”