Enhanced electron transfer by In doping in SnO₂ for efficient CO₂ electroreduction to C₁ products

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Electrocatalytic CO2 reduction is crucial for environmental and energy challenges.
• SnO2 catalysts show promise but suffer from low conductivity and poor CO2 activation, leading to high overpotentials and low current densities.

Purpose of the Study:

• To improve the selectivity and activity of SnO2-based catalysts for electrocatalytic CO2 reduction.
• To investigate the effect of Indium (In) doping on SnO2 catalyst performance for C1 product generation.

Main Methods:

• Synthesis and characterization of In-doped SnO2 catalysts.
• Electrochemical evaluation of catalysts for CO2 reduction in flow cells.
• Analysis of product selectivity and current density at various applied potentials.

Main Results:

• In-doped SnO2 achieved high selectivity (>90%) for C1 products (formate and carbon monoxide) over a wide potential range (-0.5 to -1.0 V).
• Maximum faradaic efficiency of 96.46% at -0.75 V and partial current density of -20.12 mA cm-2 at -0.95 V were recorded.
• A high current density of -166.2 mA cm-2 was achieved at -1.0 V in flow cell conditions.

Conclusions:

• Indium doping enhances the electrical conductivity and CO2 activation of SnO2 catalysts.
• Doping induces beneficial electron transfer and generates oxygen vacancies, optimizing the Sn active sites.
• Enhanced electron transfer in catalysts is key for efficient electrocatalytic CO2 reduction.