Light-Driven Synthesis of 2-Aminoethanol from Formaldehyde and Ammonia

Abstract

Amino alcohols are widely used in chemical and pharmaceutical industries, while conventional synthesis methods face drawbacks such as low selectivity and high energy consumption. Multienzyme catalysis combined with light-driven cofactor regeneration affords a platform of light-driven synthesis of chemicals, where the transfer of electrons and protons as well as the route of enzymatic reactions dominates the energy conversion efficiency and atomic economy of carbon utilization. Herein, we construct a light-driven synthesis system comprising an energy-supplying module and a multienzyme catalytic module for 2-aminoethanol synthesis from formaldehyde and ammonia. First, a S-scheme heterojunction photocatalysts with a metal–organic framework core and a bipyridine-based conjugated polymer shell are prepared as an energy-supplying module. Through synergistic intensification of proton transfer and electron transfer, the photocatalysts render cofactor (NADH) regeneration efficiency with a turnover frequency of 30.49 h^–1. Second, a multienzyme catalytic module is constructed for 2-aminoethanol synthesis in the presence of NADH. Under optimal conditions, this module produces 2-aminoethanol with an average reaction rate of 76.34 μmol L^–1 h^–1 within 24 h. Finally, the energy-supplying module is coupled with the multienzyme catalytic module for continuous synthesis of 2-aminoethanol from formaldehyde and ammonia, generating 0.55 mmol L^–1 2-aminoethanol after 4 light–dark cycles. In addition, triethanolamine (TEOA) and glucose, a biomass-derived carbon source, are both confirmed as effective electron donors for NADH regeneration and light-driven synthesis system. This work opens a pathway for the synthesis of amino alcohols and demonstrates a paradigm for the intensification of reaction processes.