Rational Design of Janus Metal Atomic‐Site Catalysts for Efficient Polysulfide Conversion and Alkali Metal Deposition: Advances and Prospects

Abstract

Although metal–sulfur batteries (M–S batteries, M = Li, Na, K) are promising next‐generation energy‐storage devices because of ultrahigh theoretical energy density, low cost, and environmentally friendliness, their practical applications are significantly hindered by the shuttle effect of polysulfides and growth of alkali metal dendrites. These issues can be mitigated by using Janus metal atomic‐site catalysts, which possess the maximum atom utilization efficiency (≈100%), adjustable electronic structures, and tailorable catalytic sites, thereby effectively improving the electrochemical performance of M–S batteries. In this review, the recent progress and development of Janus metal atomic‐sites on the properties, synthesis, and characterizations are reviewed. Then, the recent advances in Janus metal atomic‐site catalysts intended for accelerating polysulfide conversion and regulating alkali metal deposition, briefly introducing the working principles of the Janus metal atomic‐site catalysts in M–S batteries, are systematically summarized. Furthermore, a high emphasis is placed on effective regulation strategies for the rational design of Janus metal atomic‐site catalysts in M–S batteries. Finally, the current challenges and future research directions are also presented to develop high‐efficiency Janus metal atomic‐site catalysts for high‐energy M–S batteries.

Robust Activity and Stability of P-Doped Fe–Carbon Composites Derived from MOF for Bromate Reduction

“…Regarding P-doped materials, the characterization results disclose the existence of highly dispersed Fe species (Figure b–e) with Fe–N and Fe–P bonds, along with small Fe 2 P nanoclusters (Figures and S4–S7). As the P element has a larger atomic radius and higher electron-donating ability, P-doping can effectively modulate the coordination environment of Fe atoms, endowing Fe–P active sites with high activity. , Previous studies have consistently reported the effectiveness of Fe–P sites, specifically Fe 2 P and FeN 3 P 1 , in peroxymonosulfate activation and electrocatalytic oxygen reduction. , Therefore, it can be speculated that the active sites present in P-doped materials are FeN x P y and Fe 2 P. ,,, With an increase in Fe loading, the intensity of the Fe 2 P species in Fe 2 P­( x )@P­(1.0)­NC-950 increases and the reduction rate is enhanced (Figures a, a,b, and S4). The regeneration experiments revealed that the deactivated material could restore its original activity after the phosphating treatment.…”

“…26,27 Previous studies have consistently reported the effectiveness of Fe−P sites, specifically Fe 2 P and FeN 3 P 1 , in peroxymonosulfate activation and electrocatalytic oxygen reduction. 28,63 Therefore, it can be speculated that the active sites present in P-doped materials are FeN x P y and Fe 2 P. 27,63,65,66 With an increase in Fe loading, the intensity of the Fe 2 P species in Fe 2 P(x)@P(1.0)NC-950 increases and the reduction rate is enhanced (Figures 2a, 3a,b, and S4). The regeneration experiments revealed that the deactivated material could restore its original activity after the phosphating treatment.…”