Photocatalytic synthesis of biomass-based N-containing chemicals

Abstract

N-containing chemicals (NCs) serve as essential structural units in pharmaceuticals, agricultural chemicals, and fine chemicals, with market demand continuing to increase. Lignocellulosic biomass, recognized as a renewable carbon resource, contains platform molecules characterized by high reactivity and functional group diversity, making it an ideal green precursor for synthesizing high-value-added biomass-based NCs (Bio-NCs) via catalytic amide/amine reactions. Traditional thermal catalytic pathways often necessitate harsh conditions (high temperature and high pressure), complicating selectivity control. In contrast, photocatalytic technology utilizes semiconductor materials to generate photogenerated electron-hole pairs under mild conditions, enabling the precise activation of specific chemical bonds in biomass molecules. This approach has garnered attention for its potential in synthesizing Bio-NCs. This review systematically summarizes the research progress in photocatalysis for the green synthesis of Bio-NCs, focusing on the latest applications for the synthesis of amines (e.g., furfurylamine and amino acids), nitrogen-containing heterocycles (e.g., quinolizine and imidazole), and integrated systems (e.g., dehydrogenation coupling and CO₂ reduction–amine oxidation) from catalyst design, catalytic mechanism, and catalytic performance, etc. Challenges persist concerning the cost and stability of photocatalysts, the control of selectivity, the efficiency of light utilization, and the scaling-up of engineering processes. Proposed solutions have been put forth as references for advancing this field.