Abstract:

Lignocellulosic biomasses contain aromatic ring structures but have high oxygen contents. The key issue for the high value utilization of biomass-derived aromatic oxygenates is the activation and breaking of C— O bonds. There are various types of C— O bonds in biomass-derived aromatic oxygenated compounds, mainly including C_aryl—O(H) bonds connecting the carbon of the aromatic ring with the hydroxy-oxygen, ether bonds C_aryl—O—CH₃, and C\stackrel{}{̿}O bonds in the side chain of the aromatic ring. Catalytic hydrodeoxygenation (HDO) is an effective way for cleavage of C—O bonds of aromatic oxygenated compounds. This paper reviews the current research status of complete C— O bond cleavage and selective C—O bond cleavage of biomass-derived aromatic oxygenates, and describes the catalytic cleavage mechanism of C— O bond for typical aromatic oxygenates such as phenol, methylphenol, anisole, guaiacol, eugenol and vanillin. The roles of catalyst properties and structures such as hydrogenation ability, oxophilicity, acid sites, electronic structure and metal sites on C— O bond cleavage of aromatic oxygenated compounds are analyzed. Furthermore, some key issues and research focuses on the C— O bond breaking of aromatic oxygenated compounds are proposed.

Key words: biomass, aromatic oxygenates, C— O bonds, hydrodeoxygenation, catalytic mechanism

摘要：

木质生物质含有芳香环结构，但是其含氧量高。生物质衍生芳香族含氧化合物高值化利用的关键问题是其C— O键的活化断裂。生物质衍生芳香族含氧化合物中的C— O键有多种类型，主要包括连接芳环碳与羟基氧的C_aryl— O(H)键、醚键C_aryl— O— CH₃、芳环侧链中的C\stackrel{}{̿}O键等。通过催化加氢脱氧（HDO）使芳香族含氧化合物C— O键活化断裂。本文综述了生物质衍生芳香族含氧化合物的C— O键完全断裂，以及C— O键选择性断裂的研究现状；阐述了苯酚、甲基酚、苯甲醚、愈创木酚、丁香酚和香兰素等典型芳香族含氧化合物的C— O键催化断裂机理；分析了催化剂的加氢能力、亲氧性、酸位点、电子结构和金属位点等性质和结构对芳香族含氧化合物C— O键催化断裂的作用；进而提出了芳香族含氧化合物C— O键催化断裂的一些关键问题和研究重点。

关键词: 生物质, 芳香含氧化合物, C— O键, 加氢脱氧, 催化机理