摘要
木质素是自然界中丰富的可再生芳香碳资源,其解聚得到的单体可以作为重要的化工原料。以蒽醌-2-羧酸作为光催化剂,在硝基苯存在和LED光源照射下,5 h内木质素模型化合物中β-O-4键有80%的转化率。对于木质素β-O-4多聚体,该体系也表现出了光催化活性,将蒽醌-2-羧酸负载在非均相载体上,在光催化降解中也可以获得77%的底物转化率。该反应涉及了木质素β-O-4中Cα—Cβ键和Cβ—O键的断裂,在催化剂的作用下,首先发生Cα—OH的脱氢,随后经过分子内的断键和重新成键生成苯甲醛和愈创木酚。本研究加深了对光催化木质素氧化过程中C—C键断裂过程的认识,有助于理解木质素的解聚机制。
Lignin is an abundant renewable natural resource of aromatic carbon resource in nature,and the monomer obtained by its depolymerization can be used as an important chemical raw material.In this paper,anthraquinone-2-carboxylic acid was used as the photocatalyst for the depolymerization of lignin model compound.In the presence of nitrobenzene and LED light source,80%conversion of ligninβ-O-4 bond was realized within 5 hours.This system also showed photocatalytic activity towards the depolymerization of ligninβ-O-4 polymer.By loading anthraquinone-2-carboxylic acid on a heterogeneous carrier,77%substrate conversion was delivered.In this reaction,cleavage of the Cα—Cβbond and Cβ—O bond in the ligninβ-O-4 model was involved,the dehydrogenation of Cα—OH occurred firstly,and then benzaldehyde and guaiacol were generated by bonds breaking and re-bonding in the molecule.This study gives a deeper understanding of the C—C bond breaking process in the photocatalytic lignin oxidation process,which helps us understand the mechanism of ligninβ-O-4 bond depolymerization.
作者
廖声甫
刘琪英
马隆龙
LIAO Sheng-fu;LIU Qi-ying;MA Long-long(Guangzhou Institute of Energy Conversion,Chinese Academy of Sciences,Guangzhou 510640,China;CAS Key Laboratory of Renewable Energy,Guangzhou 510640,China;Guangdong Provincial Key Laboratory of New and Renewable Energy Research and Development,Guangzhou 510640,China;University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《新能源进展》
2020年第5期339-349,共11页
Advances in New and Renewable Energy
基金
国家自然科学基金项目(51536009,51976220)。
