Catalytic depolymerisation of isolated lignins to fine chemicals using a Pt/alumina catalyst: part 1-impact of the lignin structure
Catalytic depolymerisation of isolated lignins to fine chemicals using a Pt/alumina catalyst: part 1-impact of the lignin structure
复制标题
DOI：
10.1039/c4gc01678e
复制
发表时间：
2015-01-01
期刊：
影响因子：
9.8
通讯作者：
Jackson, S. David
中科院分区：
文献类型：
--
作者：
Bouxin, Florent P.;McVeigh, Ashley;Jackson, S. David
采用氧化铝负载铂催化剂对4种不同烷基芳基醚键含量的木质素进行解聚。结果表明，β - o -4键的比例是影响单体产物收率和性质的关键因素。高度缩合的木质素主要生成非烷基化的酚类产物，而未缩合的木质素主要生成保留3碳侧链的酚类产物。这些带有3碳链的酚类产物的丰度远远低于硫代酸解法选择性裂解烷基芳基醚键计算出的最大潜在产率，表明产率仍有提高的余地。虽然催化转化率随着木质素结构中不稳定醚键含量的增加而增加，但为了减少副反应，越来越需要对催化解聚进行优化。凝胶渗透色谱分析表明，无论起始原料是什么，产物都趋向于相同的分子量分布。只有在催化转化过程中缩合反应最小化后，才能充分发挥高度不缩合木质素的潜力。
Four lignin preparations with different contents of alkyl-aryl ether bonds were depolymerised using an alumina supported platinum catalyst. The results showed that the proportion of beta-O-4 linkages is the crucial factor for both the yield and the nature of the monomeric products. Highly condensed lignin generated mainly non-alkylated phenolic products while uncondensed lignin generated mainly phenolic products retaining the 3-carbon side-chain. These phenolic products with the 3-carbon chain still attached were considerably less abundant than the maximum potential yield calculated from selective cleavage of alkyl-aryl ether bonds by thioacidolysis, demonstrating that the scope for improved yield remains. Although the catalytic conversion yield rose with an increasing content of labile ether linkages in the lignin structure, optimisation of the catalytic depolymerisation was increasingly required to minimize side reactions. Gel permeation chromatography showed that the products converged towards the same molecular weight distribution regardless of the starting material. The full potential of the highly uncondensed lignin was reached only after the minimisation of condensation reactions during the catalytic conversion.