Toward high-selectivity CO₂ photoelectroreduction: mechanistic foundations, recent advances and challenges.

Area of Science:

• Electrochemistry
• Catalysis
• Materials Science

Background:

• Photoelectrochemical carbon dioxide reduction (PEC CO2RR) offers a sustainable route for converting CO2 into high-value chemicals.
• Achieving high product selectivity in PEC CO2RR is critical for process efficiency, yield, and economic viability.
• Competitive reaction pathways often lead to a mixture of products, complicating separation and reducing overall efficiency.

Purpose of the Study:

• To systematically review recent advances and challenges in enhancing product selectivity for PEC CO2RR.
• To explore key factors influencing selectivity, including catalyst design, reaction conditions, and reactor engineering.
• To summarize progress in C1 and C2 product formation and identify future research directions.

Main Methods:

• Discussion of catalyst design strategies (type, modification, composition, morphology).
• Analysis of reaction condition optimization (voltage, light, temperature, electrolyte).
• Evaluation of reactor design parameters (electrode area, synergistic effects, structure, gas diffusion).

Main Results:

• Identified key factors influencing PEC CO2RR selectivity, including catalyst properties, electrolyte composition, and reactor configuration.
• Reviewed progress in selective synthesis of C1 and C2 products over the last five years.
• Summarized challenges in reaction stability and identified strategies for long-term selectivity.

Conclusions:

• Optimizing catalyst design, reaction conditions, and reactor engineering is essential for high PEC CO2RR selectivity.
• Further research into reaction mechanisms, stability, and industrial scalability is needed.
• Innovative approaches in catalyst development and system design are crucial for advancing PEC CO2RR applications.