# Water‐Soluble Metal Phthalocyanines Enable Molecularly Dispersed Heterogeneous Electrochemical CO2 Conversion

## TL;DR

Scientists developed a new method to convert CO2 into CO using water-soluble metal compounds attached to carbon, achieving high efficiency and stability.

## Contribution

A generalizable strategy to disperse molecular electrocatalysts on carbon black for efficient CO2 electroreduction.

## Key findings

- MPcTs/CB catalyst achieves near-quantitative Faradaic efficiency for CO2-to-CO conversion.
- Sustained performance over 60 hours with high CO selectivity.
- Flow-cell configurations reach 500 mA cm−2 current density with high CO selectivity.

## Abstract

Molecular electrocatalysts offer the prospect of atomically defined active sites and tunable reactivity, yet their integration into heterogeneous systems is frequently hindered by limited site accessibility and reduced catalytic performance. Overcoming molecular aggregation and improving electronic coupling with conductive supports are essential for translating molecular precision into practical electrocatalytic devices. Here we show that water‐soluble, tetrasulfonate‐substituted metallophthalocyanines (MPcTs) spontaneously assemble onto carbon black (CB) through π–π interactions, forming highly dispersed and electronically coupled catalytic sites. The resulting MPcTs/CB catalyst enables highly selective CO2‐to‐CO conversion in aqueous media, affording near‐quantitative Faradaic efficiencies and sustained performance over 60 h of continuous operation. Systematic investigations confirm a heterogeneous electrocatalytic pathway, while optimized flow‐cell configurations deliver current densities up to 500 mA cm−
2 with high CO selectivity. This study demonstrates a simple, generalizable strategy to bridge molecular precision and heterogeneous practicality, advancing the design of scalable, high‐performance molecular electrocatalysts for CO2 electroreduction in aqueous media.

Water‐soluble metallophthalocyanines self‐assemble onto the surface of carbon black via π–π interactions, creating highly dispersed and electronically coupled MPcTs/CB, which enables selective CO2‐to‐CO conversion in aqueous media with near‐quantitative Faradaic efficiency and remarkable stability. Optimized flow‐cell operation delivers up to 500 mA cm−2 with high CO selectivity, offering a scalable strategy for advanced CO2 electrocatalysis.