Targeted conversion of model phenolics in pyrolysis bio-oils to arenes via hydrodeoxygenation over MoOx/BaO@SBA-15 catalyst
Targeted conversion of model phenolics in pyrolysis bio-oils to arenes via hydrodeoxygenation over MoOx/BaO@SBA-15 catalyst
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DOI：
10.1016/j.cej.2022.135577
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发表时间：
2022-06
影响因子：
15.1
通讯作者：
Hongzi Tan;Siteng Rong;Rongrong Zhao;Hongyou Cui;Ning-ning Zhang;Zhe-ning Chen;Zhihe Li;Weiming Yi;Fengshan Zhang
中科院分区：
文献类型：
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作者：
Hongzi Tan;Siteng Rong;Rongrong Zhao;Hongyou Cui;Ning-ning Zhang;Zhe-ning Chen;Zhihe Li;Weiming Yi;Fengshan Zhang
木质素快速热解生成的生物油中含有大量的酚类成分。由于含氧量高，这些生物油不能用作交通液体燃料。加氢脱氧（HDO）是将这些酚类化合物升级为芳烃等高附加值化学品的有效策略。然而，将酚类化合物升级为芳烃的挑战在于含氧基团（例如-OCH 3和-OH）的选择性氢解，同时保持不饱和芳环完整。然而，产生的中间体的竞争吸附行为可能会抑制苯酚进一步HDO芳烃。本文合成了富氧缺陷的MoOx/SBA-15催化剂，该催化剂能够诱导酚类化合物以“非平面”方式吸附，削弱CAr-OR（R = CH 3或H）键的强度，防止芳环的过度氢化。此外，在MoOx/SBA-15表面修饰BaO涂层，调节其表面酸碱性质，促进苯酚的吸附，并通过与苯酚的烷基化反应消耗甲醇，提高愈创木酚一步HDO转化为苯和甲苯的能力。基于催化剂评价和表征以及密度泛函理论（DFT）计算，分析和讨论了MoOx/BaO@SBA-15催化酚类HDO反应的催化机理。本研究不仅有助于深入了解混合酚类化合物HDO反应的竞争相互作用，而且有助于设计和合成高效的HDO催化剂，用于将生物原油改质为芳烃。
The bio-oils derived from fast pyrolysis of lignin contain large amount of phenolic components. Owing to the high oxygen content, these bio-oils could not be used as traffic liquid fuels. Hydrodeoxygenation (HDO) was an effective strategy to upgrade these phenolics into high value-added chemicals such as arenes. However, the challenge of upgrading phenolics into arenes lies in selective hydrogenolysis of the oxygen-containing groups (e.g.–OCH3and –OH) while keeping the unsaturated aromatic rings intact. However, the competitive adsorption behavior of produced intermediates likely inhibits the further HDO of phenol to arenes. In this work, MoOx/SBA-15 with rich oxygen defects was synthesized, which is capable of inducing phenolics adsorbed in a “nonplanar” manner, weakening the intensity of CAr-OR (R = CH3or H) bonds and preventing the excessive hydrogenation of aromatic rings. In addition, BaO coating was decorated on MoOx/SBA-15 to tune the surface acid-base properties so as to promote the adsorption of phenol and consume MeOH via alkylation reaction with phenol, enhancing guaiacol one-step HDO into benzene and toluene. Based on catalyst evaluation and characterization as well as density functional theory (DFT) calculations, the catalytic mechanism of phenolics HDO reaction over MoOx/BaO@SBA-15 was analyzed and discussed. Current work helps not only gain deep insights into the competitive interaction for mixed phenolics HDO reaction, but also shed light on the design and synthesis of high-efficient HDO catalysts for upgrading crude bio-oils into arenes.