Hydrogen Borrowing: towards Aliphatic Tertiary Amines from Lignin Model Compounds Using a Supported Copper Catalyst.

Area of Science:

• Chemical Engineering
• Catalysis
• Renewable Energy

Background:

• Biorefineries are emerging to produce renewable chemicals from biomass.
• Lignin valorization yields aromatic compounds with aliphatic alcohols.
• Sustainable synthesis of amines from these alcohols is crucial.

Purpose of the Study:

• To develop a catalytic hydrogen borrowing method for synthesizing tertiary amines.
• To utilize lignin-derived monomers and dimethylamine as reactants.
• To identify an effective and reusable catalyst system.

Main Methods:

• Screening of various industrial metal catalysts.
• Hydrogen borrowing reaction using lignin model and actual monomers with dimethylamine.
• Kinetic studies to elucidate reaction networks.
• Catalyst characterization using ToF-SIMS, N2O chemisorption, TGA, and XPS.

Main Results:

• Cu-ZrO2 demonstrated high alcohol conversion and good tertiary amine selectivity.
• Low H2 pressure favored catalyst activity and selectivity by preventing side reactions.
• Catalyst deactivation was linked to product desorption and copper species loss.
• Thermal reduction successfully restored catalyst performance.

Conclusions:

• Cu-ZrO2 is a suitable catalyst for producing tertiary amines from lignin-derived alcohols.
• The catalytic system is robust and reusable after thermal regeneration.
• This method provides a sustainable pathway for renewable aromatic amine production.