Modulating Electronic Structure of Amorphous Indium Oxide for Efficient Formate Synthesis Towards CO₂...

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Optimizing catalyst electronic structure is key for efficient CO2 electroreduction.
• Amorphous indium oxide (InOx) shows promise but requires structural enhancement.

Purpose of the Study:

• To develop an efficient catalyst for CO2 electroreduction by tuning the electronic structure of amorphous InOx.
• To enhance catalyst-substrate interfaces for improved electron transfer.

Main Methods:

• Construction of amorphous InOx with a cotton-like structure on a nitrogen-doped carbon (N-C) substrate.
• Electrochemical testing to measure current density and faradaic efficiency for formate production.
• Density functional theory (DFT) calculations to investigate reaction mechanisms.

Main Results:

• The InOx/N-C catalyst achieved a current density of -34.4 mA cm⁻².
• Faradaic efficiency for formate (HCOO⁻) reached 79.6% at -1.0 V vs RHE, significantly higher than InOx on carbon black (44.2%).
• N-C substrate accelerated charge transfer and facilitated HCOO⁻ protonation while inhibiting hydrogen evolution.

Conclusions:

• The N-C substrate effectively enhances the catalytic performance of amorphous InOx for CO2 electroreduction.
• The synergistic interaction between InOx and N-C promotes formate production by optimizing reaction pathways.