Zn Single Atom Catalyst for Highly Efficient Oxygen Reduction Reaction

Abstract

The authors report first a new type of nitrogen-triggered Zn single atom catalyst, demonstrating high catalytic activity and remarkable durability for the oxygen reduction reaction process. Both X-ray absorption fine structure spectra and theoretical calculations suggest that the atomically dispersed Zn-N 4 site is the main, as well as the most active, component with O adsorption as the rate-limiting step at a low overpotential of 1.70 V. This work opens a new field for the exploration of high-performance Pt-free electrochemical oxygen reduction catalysts for fuel cells.

Efficient Oxygen Reduction Catalysts of Porous Carbon Nanostructures Decorated with Transition Metal Species

“…However, it is difficult to synthesize desired catalysts with accurate metal content and uniform distribution of metal atoms. Carbon black (support), zinc acetate (Zn source), and urea (N source) have been used to prepare Zn single atom catalyst (ZnN x /BP), which showed high surface area (1383.9 m 2 g −1 ) and excellent ORR activity ( E onset = ≈1.008 V, E 1/2 = ≈0.833 V) in alkaline solution as shown in Figure 5 a–c 85. This method allows scalable synthesis of catalysts with good reproducibility and effective control of the heteroatom dopants by optimizing the pyrolyzing temperature.…”

“…c) LSV curves of ZnN x /BP and other counterparts. Reproduced with permission 85. Copyright 2017, Wiley‐VCH.…”

Stimulated Electrocatalytic Hydrogen Evolution Activity of MOF‐Derived MoS2 Basal Domains via Charge Injection through Surface Functionalization and Heteroatom Doping

“…Specifically, Zn in MoS-CoS-Zn possesses higher peak intensity and positive shift in the absorption edge compared with MoS-CoS-Zn-1pot (Figure 4d inset), which suggests that Zn is more positively charged, and therefore more electron transfer could occur from Zn to MoS-CoS hybrid in MoS-CoS-Zn, coinciding with the XPS spectra data. [44][45][46] To further reveal the electronic environment modulation, and to verify the Zn atom coordination, X-ray absorption fine structure measurements on Co ( Figure S25, Supporting Information) and Mo K-edges ( Figure S26, Supporting Information) were also carried out. This finding is corroborated by Fourier-transformed EXAFS (FT-EXAFS) spectra of MoS-CoS-Zn, MoS-CoS-Zn-1pot, and ZnS.…”

Nitrogen‐Doped Porous Carbon Supported Nonprecious Metal Single‐Atom Electrocatalysts: from Synthesis to Application

“…A sufficient amount of N source provides additional defect sites and N coordination groups for metal atoms during pyrolysis. Inspired by similar Co, Fe, Zn porphyrin structures in blood cells, Song et al prepared Zn SA‐N/C catalyst by pyrolysis of carbon black (BP2000), urea (N precursor) and zinc acetate (metal precursor), and Zn and N codoping form more defect sites and abundant pores . HAADF‐STEM confirmed that Zn is in the form of single atom, and extended EXAFS confirms that the structure of Zn single atom is Zn‐N 4 which has high catalytic activity and significant durability in oxygen reduction reaction.…”

“…The onset and E 1/2 of Zn‐N x /C were 0 and 0.825 mV respectively when the content of Zn was 0.30 wt%, which can compare to Pt/C (Pt 20 wt%), suggesting promising electrocatalytic activity for ORR. The reaction mechanism showed that the adsorption of the O atom intermediate is the rate‐determining step in the reaction of Zn‐N x /C …”