Photocatalytic Transfer Hydrogenation Using Plastic Hydrolysates as Hydrogen Donor

Area of Science:

• Green Chemistry
• Catalysis
• Materials Science

Background:

• Traditional synthesis of aromatic amines relies on harsh conditions or fossil-derived hydrogen (H2).
• A sustainable and efficient alternative for aniline production is needed.
• Plastic waste represents an underutilized resource for chemical synthesis.

Purpose of the Study:

• To develop a photocatalytic transfer hydrogenation (PTH) method for converting nitroarenes to anilines.
• To utilize plastic hydrolysates as sustainable hydrogen donors.
• To evaluate the efficiency and economic viability of the developed process.

Main Methods:

• Photocatalytic transfer hydrogenation (PTH) using a cobalt-promoted molybdenum sulfide (CoMoS2) electrocatalyst and a carbon nitride (CNx) semiconductor photocatalyst.
• Reduction of nitroarenes to anilines in acidic aqueous solution under ambient conditions.
• Utilizing acid-hydrolyzed plastic polymers (e.g., PET) as a source of hydrogen donors (alcoholic monomers).
• Simulated solar light (AM 1.5G) and LED irradiation for driving the photocatalytic reaction.

Main Results:

• The CoMoS2-CNx photocatalyst achieved high yields (83%-99%) for 24 different nitroarenes.
• The process demonstrated superior activity compared to platinum-based catalysts.
• Plastic hydrolysates were effectively used as sustainable hydrogen donors, yielding >80% anilines.
• Technoeconomic analysis indicated a ~77% reduction in cradle-to-gate emissions compared to conventional methods.

Conclusions:

• Photocatalytic transfer hydrogenation using plastic hydrolysates offers a sustainable and efficient route to aniline synthesis.
• The CoMoS2-CNx system presents a promising alternative to fossil-fuel-dependent hydrogenation processes.
• This approach contributes to a circular economy by valorizing plastic waste.