Efficient CO₂ Conversion through a Novel Dual-Fiber Reactor System

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• Photocatalytic reduction of carbon dioxide (CO2) to valuable organic chemicals is promising but limited by light-energy loss and low efficiency.
• Existing methods suffer from poor conversion rates, low quantum efficiency (QE), and inefficient CO2 delivery.

Purpose of the Study:

• To develop an efficient photocatalytic reactor platform for producing formic acid (HCOOH) from CO2.
• To overcome the limitations of light-energy loss, poor conversion efficiency, and low QE in current photocatalytic systems.

Main Methods:

• Coating an amine-group decorated iron-based metal-organic framework (Fe-MOF) onto side-emitting polymeric optical fibers (POFs).
• Utilizing hollow-fiber membranes (HFMs) for bubble-free CO2 delivery.
• Employing a dual-fiber system integrating Fe-MOF coated POFs and HFMs.

Main Results:

• Achieved a CO2-to-HCOOH conversion rate of 116 ± 1.2 mM h−1 g−1, which is 18-fold higher than slurry systems.
• Obtained a QE of 12% using POF, 18-fold greater than photocatalytic slurry.
• Demonstrated up to 22% conversion efficiency and 99% product selectivity for CO2-to-HCOOH.
• Reported energy consumption of 0.60 ± 0.05 kWh mol−1, 3000-fold better than slurry systems.

Conclusions:

• The developed dual-fiber photocatalytic reactor platform significantly enhances CO2 valorization efficiency and reduces energy consumption.
• The innovative design, utilizing Fe-MOF coated POFs and bubble-free CO2 delivery, offers a sustainable solution for CO2 conversion.
• This method avoids the need for platinum group metals or rare earth elements, promoting cost-effective and environmentally friendly applications.