P‐Block Atomically Dispersed Antimony Catalyst for Highly Efficient Oxygen Reduction Reaction

Abstract

Main‐group (s‐ and p‐block) metals are generally regarded as catalytically inactive due to the delocalized s/p‐band. Herein, we successfully synthesized a p‐block antimony single‐atom catalyst (Sb SAC) with the Sb−N4 configuration for efficient catalysis of the oxygen reduction reaction (ORR). The obtained Sb SAC exhibits superior ORR activity with a half‐wave potential of 0.86 V and excellent stability, which outperforms most transition‐metal (TM, d‐block) based SACs and commercial Pt/C. In addition, it presents an excellent power density of 184.6 mW cm−2 and a high specific capacity (803.5 mAh g−1) in Zn–air battery. Both experiment and theoretical calculation manifest that the active catalytic sites are positively charged Sb−N4 single‐metal sites, which have closed d shells. Density of states (DOS) results unveil the p orbital of the atomically dispersed Sb cation in Sb SAC can easily interact with O2‐p orbital to form hybrid states, facilitating the charge transfer and generating appropriate adsorption strength for oxygen intermediates, lowering the energy barrier and modulating the rate‐determining step. This work sheds light on the atomic‐level preparing p‐block Sb metal catalyst for highly active ORR, and further provides valuable guidelines for the rational design of other main‐group‐metal SACs.

P-block tin single atom catalyst for improved electrochemistry in a lithium–sulfur battery: a theoretical and experimental study

“…This charge transfer makes Sn–N 4 a highly polar site for the polysulfide adsorption because the positive Sn atom can account for the S x anion binding site and the electron-rich ligand atoms can act as the Lewis base to form a bond with lithium. 45,56…”

“…In previous reports, the SACs employed in Li–S batteries were all based on d-block transition metals, in which the partially filled d bands are the origin of the electrocatalysis activities. 45 Compared with the d-block transition metal elements, the p-block elements show outstanding stability due to the poor electronic flexibility. 46 Surface engineering, like the N-doped carbon supported single p-block metal atom materials, offers a wealth of pathways for activating p-block materials.…”

“…Interestingly, some highly inspiring research studies have revealed that the p-block metals can be activated for electrocatalysis, taking advantage of the M–N x coordination configuration. 45,47–50 For instance, single metal atom catalysts with Sn–N x , Sb–N 4 sites displayed high activities and high 4e − reaction selectivity towards the oxygen reduction reaction (ORR). 45,49,50 Novel studies have engineered the coordination environments of the Sn, In and Sb metal-based M–N x sites, and successfully modulated the selectivity and efficiency of the single atom catalysts for CO 2 reduction reaction.…”

“…45,47–50 For instance, single metal atom catalysts with Sn–N x , Sb–N 4 sites displayed high activities and high 4e − reaction selectivity towards the oxygen reduction reaction (ORR). 45,49,50 Novel studies have engineered the coordination environments of the Sn, In and Sb metal-based M–N x sites, and successfully modulated the selectivity and efficiency of the single atom catalysts for CO 2 reduction reaction. 51 Regarding the single metal atom catalysts for Li–S batteries, it is highly instructive to expand the metal catalogue to the p-block metals.…”

Tailoring the Electronic Structure of an Atomically Dispersed Zinc Electrocatalyst: Coordination Environment Regulation for High Selectivity Oxygen Reduction

“…The accumulation of electrons around O implied that O captures more electrons from Zn compared with N attributed to the stronger electronegativity of O. [26] Moreover, compared with ZnN 4 , it was observed that the d-band center of ZnO 3 C downshifts away from the Fermi level (Figure 4 c), which would definitely affect the adsorption strength between oxygenated intermediates and metal active sites (Figure S18). [27] The free energy diagram of 2 e À /4 e À ORR pathway intermediates on ZnO 3 C and ZnN 4 at 0 V is displayed in Figure 4 d and Tables S8 and S9.…”