Microwave‐Assisted Decarbonylation of Biomass‐Derived Aldehydes using Pd‐Doped Hydrotalcites
Microwave‐Assisted Decarbonylation of Biomass‐Derived Aldehydes using Pd‐Doped Hydrotalcites
复制标题
使用 Pd 掺杂水滑石进行微波辅助生物质脱羰基衍生醛
DOI：
10.1002/cssc.201901934
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发表时间：
2019
期刊：
影响因子：
8.4
通讯作者：
Voutchkova‐Kostal, Adelina
中科院分区：
文献类型：
--
作者：
An, Nan;Ainembabazi, Diana;Reid, Christopher;Samudrala, Kavya;Wilson, Karen;Lee, Adam F.;Voutchkova‐Kostal, Adelina
由于缺乏可在良性溶剂中运行的低成本且稳定的多相催化剂，催化脱羰是一种尚未充分探索的生物质醛脱氧策略。合成、表征了一系列 Pd 功能化水滑石 (Pd-HT)，并将其应用于微波条件下糠醛、5-羟甲基糠醛 (HMF) 以及芳香族和脂肪族醛的脱羰。即使在低 Pd 负载量 (0.5 mol %) 下，该催化系统也能提高脱羰产率和周转频率。在与生物质加工兼容的良性溶剂（乙醇）中对糠醛脱羰进行了优化； HMF 选择性地提供了优异的糠醇收率 (93%)，且没有胡敏素形成；然而，较长的反应有利于通过串联醇脱氢和脱羰形成呋喃。取代苯甲醛的产率 (37–99%) 与计算出的羰基碳的马利肯电荷成正比。活性和选择性反映了负载依赖性的 Pd 形态。最佳 Pd-HT 催化剂的连续流动测试在运行 16 小时内表现出良好的稳定性，并且 HMF 的转化率接近定量。
Catalytic decarbonylation is an underexplored strategy for deoxygenation of biomass‐derived aldehydes owing to a lack of low‐cost and robust heterogeneous catalysts that can operate in benign solvents. A family of Pd‐functionalized hydrotalcites (Pd‐HTs) were synthesized, characterized, and applied to the decarbonylation of furfural, 5‐hydroxymethylfurfural (HMF), and aromatic and aliphatic aldehydes under microwave conditions. This catalytic system delivered enhanced decarbonylation yields and turnover frequencies, even at a low Pd loading (0.5 mol %). Furfural decarbonylation was optimized in a benign solvent (ethanol) compatible with biomass processing; HMF selectively afforded an excellent yield (93 %) of furfuryl alcohol without humin formation; however, a longer reaction favored the formation of furan through tandem alcohol dehydrogenation and decarbonylation. Yields of the substituted benzaldehydes (37–99 %) were proportional to the calculated Mulliken charge of the carbonyl carbon. Activity and selectivity reflected loading‐dependent Pd speciation. Continuous‐flow testing of the best Pd‐HT catalyst delivered good stability over 16 h on stream, with near‐quantitative conversion of HMF.