Selectively breaking the C-O bonds within biomass during catalytic fast pyrolysis (CFP) is desired, but extremely challenging. Herein, we develop a series of metal-oxide nanocomposites composed of W, Mo, Zr, Ti, or Al. It is demonstrated that the nanocomposites of WO₃-TiO₂-Al₂O₃ exhibit the highest deoxygenation ability during CFP of lignin, which can compete with the commercial HZSM-5 catalyst. The nanocomposites can selectively cleave the C-O bonds within lignin-derived phenols to form aromatics by direct demethoxylation and subsequent dehydration. Moreover, the nanocomposites can also achieve the selective breaking of the C-O bonds within xylan and cellulose to form furans by dehydration. The Brønsted and Lewis acid sites on the nanocomposites can be responsible for the deoxygenation of lignin and polysaccharides, respectively. This study provides new insights for the rational design of multifunctional catalysts that are capable of simultaneously breaking the C-O bonds within lignin and polysaccharides.

期望在催化快速热解（CFP）期间选择性地破坏生物质内的CO键，但是极具挑战性。本文中，我们开发了一系列由W，Mo，Zr，Ti或Al组成的金属氧化物纳米复合材料。证明了WO ₃ -TiO ₂ -Al ₂ O ₃的纳米复合材料在木质素的CFP过程中具有最高的脱氧能力，可与商业HZSM-5催化剂竞争。纳米复合材料可以通过直接脱甲氧基化和随后的脱水选择性地裂解木质素衍生的酚内的CO键以形成芳族化合物。此外，纳米复合材料还可通过脱水使木聚糖和纤维素内的CO键选择性断裂以形成呋喃。纳米复合材料上的布朗斯台德和路易斯酸位点分别负责木质素和多糖的脱氧。这项研究为多功能催化剂的合理设计提供了新见解，这些催化剂能够同时破坏木质素和多糖中的CO键。