Asymmetric CoN₃P₁ Trifunctional Catalyst with Tailored Electronic Structures Enabling Boosted Activities and Corrosion Resistance in an Uninterrupted Seawater Splitting System

Abstract

Employing seawater splitting systems to generate hydrogen can be economically advantageous but still remains challenging, particularly for designing efficient and high Cl−‐corrosion resistant trifunctional catalysts toward the oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction (HER). Herein, single CoNC catalysts with well‐defined symmetric CoN4 sites are selected as atomic platforms for electronic structure tailoring. Density function theory reveals that P‐doping into CoNC can lead to the formation of asymmetric CoN3P1 sites with symmetry‐breaking electronic structures, enabling the affinity of strong oxygen‐containing intermediates, moderate H adsorption, and weak Cl− adsorption. Thus, ORR/OER/HER activities and stability are optimized simultaneously with high Cl−‐corrosion resistance. The asymmetric CoN3P1 structure based catalyst with boosted ORR/OER/HER performance endows seawater‐based Zn–air batteries (S‐ZABs) with superior long‐term stability over 750 h and allows seawater splitting to operate continuously for 1000 h. A self‐driven seawater splitting powered by S‐ZABs gives ultrahigh H2 production rates of 497 μmol h−1. This work is the first to advance the scientific understanding of the competitive adsorption mechanism between Cl− and reaction intermediates from the perspective of electronic structure, paving the way for synthesis of efficient trifunctional catalysts with high Cl−‐corrosion resistance.

Amorphous Co-Mo-B Film: A High-Active Electrocatalyst for Hydrogen Generation in Alkaline Seawater

“…The following supporting information can be downloaded at: , refs. [ 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 ] are cited in this file. Figure S1: (a) Low- and (b) high-magnification SEM images of bare NF; Figure S2: (a) Low- and (b) high-magnification SEM images of Co-B/NF; Figure S3: EDX spectrum of Co-Mo-B/NF; Figure S4: XPS survey spectrum of Co-Mo-B/NF; Figure S5: LSV curves of Co-Mo-B/NF, Co-B/NF, Pt/C, and bare NF for HER in 1 M KOH with a scan rate of 5 mV s –1 (without IR correction); Figure S6: CV curves for Co-Mo-B/NF (a), Co-B/NF (b), and bare NF (c) in the non-Faradaic capacitance current range at scan rates of 20, 40, 60, 80, and 100 mV s –1 in 1 M KOH; Figure S7: LSV curves of Co-Mo-B/NF in 1 M KOH, 1 M KOH + 0.5 M NaCl, and 1 M KOH + seawater with a scan rate of 5 mV s –1 (without IR correction); Figure S8: High-resolution XPS spectra of (a) Co 2p, (b) Mo 3d, (c) B 1s, and (d) O 1s regions for Co-Mo-B/NF after stability test in alkaline seawater; Figure S9: The Faradaic efficiency of Co-Mo-B/NF at 100 mA cm –2 in alkaline seawater; Table S1: Comparison of HER performance of Co-Mo-B/NF with recent reported electrocatalysts in alkaline freshwater; Table S2: Comparison of HER performance of Co-Mo-B/NF with recent reported electrocatalysts in alkaline seawater.…”

Tailoring charge reconfiguration in dodecahedral Co2P@carbon nanohybrids by triple-doping engineering for promoted reversible oxygen catalysis

“…In addition, because phosphorus (P) has a weaker electronegativity than N, incorporating the secondary heteroatom P would lead to the formation of an unsymmetrical N/P coordination structure, which could undergo a symmetry-breaking charge transfer process and trigger the modulation of the electronic structure of active metal sites. 88 Due to its highest P–C content (Table S5†), the optimized electronic structure of the Fe-Co 2 P@NPDC catalyst enables the metal–N/P active sites to exhibit suitable adsorption/desorption energy barriers for various reaction intermediates (*OOH, *O, and *OH), thus resulting in the promoted electrocatalytic ORR/OER activities (Fig. 5).…”

Atomically dispersed Mn atoms coordinated with N and O within an N-doped porous carbon framework for boosted oxygen reduction catalysis

“…Furthermore, the tailored electronic structure can endow the asymmetric Co–N 3 P 1 moiety with reduced reaction barriers compared to the common Co–N 4 structure, enabling high ORR performance in an alkaline electrolyte. 18 Thus, introducing heteroatoms can efficiently tune the coordinated micro-environment of single metal active centers, and the electrocatalytic ORR activity can be significantly enhanced. However, rational design of stable and highly efficient nanomaterials with boosted ORR electrochemical activity in a wide pH range still remains a challenge, which severely hinders the practical applications of atomically dispersed metal-based electrocatalysts.…”