Synergistic Zn-Cd Bimetallic Engineering in ZIFs for High-Chloride 2e− ORR to H2O2 in Simulated Neutral Seawater

TL;DR

A new bimetallic catalyst efficiently produces hydrogen peroxide in seawater-like conditions, offering a cleaner alternative to traditional antifouling methods.

Contribution

The novel Zn-Cd bimetallic ZIF catalyst enables high H2O2 selectivity and resistance to chloride in neutral seawater conditions.

Findings

ZnCd-ZIF achieves 70% H2O2 selectivity at 0.3 VRHE in simulated seawater.

H2O2 production reaches 120 mmol g−1 with resistance to chloride and corrosion.

Outperforms monometallic Zn-ZIF and Cd-ZIF in chloride-rich neutral electrolytes.

Abstract

Marine biofouling causes significant economic losses, and conventional antifouling methods are often associated with environmental pollution. Hydrogen peroxide (H2O2), as a clean energy source, has gained increasing attention in recent years. Meanwhile, electrocatalytic 2e− oxygen reduction reaction (ORR) for H2O2 production has received growing interest. However, the majority of current studies are conducted on acidic or alkaline electrolytes, and research on 2e− ORR in neutral NaCl solutions remains rare. Here, a bimetallic Zn-Cd zeolitic imidazolate framework (ZnCd-ZIF) is rationally designed to achieve chloride-resistant 2e− ORR catalysis under simulated seawater conditions (pH 7.5, 3.5% Cl−). Experimental results demonstrate that the ZnCd-ZIF catalyst exhibits an exceptional H2O2 selectivity of 70% at 0.3 VRHE, surpassing monometallic Zn-ZIF (60%) and Cd-ZIF (50%). Notably, H2O2 production reaches 120 mmol g−1 in a Cl−-containing neutral electrolyte, exhibiting strong resistance to structural corrosion and Cl− poisoning. This work not only pioneers an effective strategy for designing ORR catalysts adapted to marine environments but also advances the practical implementation of seawater-based electrochemical H2O2 synthesis.

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