Abstract Long-chain oxygenated liquid fuels have similar physicochemical properties with diesel fuel, and its oxygen can promote combustion and reduce PM2.5. An approach for the preparation of the precursor from lignocellulose suitable for C C coupling is the key problem to be solved in the production of long-chain oxygenated fuels. In this work, cellulose, as a main component in biomass, was directly alcoholyzed to carbonyl compounds with α-H catalyzed by three typical metal oxides (CaO, MgO and ZnO). The results showed that high temperature was favorable for the conversion of cellulose, but a large number of side products, namely levoglucosan and ethyl-α-D-pyran glucoside, have been detected in liquefied products. These by-products could be transformed into target precursors with α-H over CaO or ZnO with 0.5 mmol at 320 °C in ethanol solvent. Additionally, side reactions of ethanol at elevated temperature could be inhibited with ZnO in water-ethanol co-solvent and the by-products from ethanol dehydration, including 1,1-diethoxyethane, 2-ethoxyethanol, dropped significantly with an increase in carbonyl compounds. Noticeably, compared with pure ethanol, the yield of carbonyl compounds in liquid products increased obviously to 47.4% when the volume ratio of water to ethanol was 3: 10.

中文翻译：

---

金属氧化物催化纤维素乙醇分解制备长链氧化燃料羰基前体

摘要 长链含氧液体燃料具有与柴油相似的理化性质，其氧气具有促进燃烧、降低PM2.5的作用。一种适用于CC偶联的木质纤维素前体制备方法是长链含氧燃料生产中需要解决的关键问题。在这项工作中，纤维素作为生物质中的主要成分，在三种典型的金属氧化物（CaO、MgO 和 ZnO）的催化下，用 α-H 直接醇化为羰基化合物。结果表明，高温有利于纤维素的转化，但在液化产物中检测到大量的副产物，即左旋葡聚糖和乙基-α-D-吡喃葡糖苷。在 320°C 的乙醇溶剂中，这些副产物可以在 CaO 或 ZnO 上用 0.5 mmol 的 α-H 转化为目标前体。此外，水-乙醇共溶剂中的氧化锌可以抑制乙醇在高温下的副反应，乙醇脱水的副产物，包括 1,1-二乙氧基乙烷、2-乙氧基乙醇，随着羰基化合物的增加而显着下降。值得注意的是，与纯乙醇相比，当水与乙醇的体积比为3:10时，液体产品中羰基化合物的产率明显提高至47.4%。