碳化钨催化生物基环己烯衍生物原子经济反应制芳香化学品

Para-xylene (PX) and oxygen-containing aromatics are indispensable commodity building blocks for chemical industry that derived from fossil resources. With the diminishing fossil resource and the growing worldwide concern about environmental problem, development of renewable route to valuable aromatics from biomass resource is of great significance to sustainable society. This project put forward a new route for the production of PX and oxygen-containing aromatics with high selectivity from biomass-derived platform compounds via simple two step reactions: first, six-membered ring precursors will be synthesized through Diels-Alder reaction of bio-based diene (such as isoprene) and dienophile (acrolein, etc.) in Lewis acid ionic liquid; then, a tungsten carbide catalyzed gaseous-phase dehydrogenation reaction followed by in-situ hydrodeoxygenation affords PX with high overall yield, and the cascade reaction mechanism of over tungsten carbide via hydrogen transfer will be deeply explored. With the aim to control the products selectivity, the competitive reaction mechanisms of decarbonylation and hydrodeoxygenation of six-membered ring precursor on tungsten carbide surface will be studied as well through in-situ physical and chemical characterization. Based on the above progress, rational modification of the tungsten-based catalyst will be explored with the aim to restrain the hydrodeoxygenation activity and thus obtain value-added oxygen-containing aromatics. This project is highly atom-economic as almost all of the carbon atoms are preserved in the product. Implementation of this project will set up some theoretic rules in the development of non-noble metal carbide catalysts for biomass conversion and opens a new window for cost-efficient production of aromatic chemicals from lignocellulose.

对二甲苯（PX）等芳香化学品来源于化石资源，对国民经济发展起不可替代的作用。利用生物质资源开发原子经济合成路线意义重大。本项目以PX等芳烃及含氧芳香化学品为目标，以生物基异戊二烯和丙烯醛及衍生物为原料，在Lewis酸离子液体作用下构建六元环前驱体环己烯衍生物，随后通过碳化钨催化六元环前驱体气相脱氢-加氢脱氧反应制PX，借助多种原位表征手段重点研究碳化钨作用下串联反应高效耦合的催化机理和分子内氢转移的独特作用，阐明加氢脱氧和脱羰基反应在碳化钨表面的竞争机制，实现产物选择调控；进一步拓展底物，发展原子经济制备生物基芳烃的普适方法。在深入理解催化作用机制的基础上，通过对钨基催化剂改性抑制加氢脱氧活性，调控产物为更高价值含氧芳香化学品。本项目力争实现底物碳原子在产物中完全保留，为从廉价生物质资源到芳香化学品的高值化转化提供新思路，同时为拓展非贵金属碳化物催化剂在涉氢反应中应用提供重要理论支撑。

在双碳目标大背景下，利用生物质资源开发芳烃产业链对可持续经济的发展至关重要。本项目以高值/大宗芳香化学品为目标，利用量大面广的生物质平台化合物资源为原料，建立了生物质路线制对二甲苯（PX）等芳烃及含氧芳香化学品的新路线。采用Lewis酸离子液体为催化剂，以生物基异戊二烯和丙烯醛为原料，高效构建了六元环前驱体，随后分别开发了FeOx修饰的Pd/Al2O3和碳化钨催化剂催化气相脱氢-加氢脱氧反应制PX，借助多种表征手段阐明了串联反应高效耦合的催化机理和分子内氢转移的独特作用，通过对催化剂性质调控，实现产物选择调控，并形成了制其它生物基芳烃的普适方法。项目在Nature Communications、Angewandte Chemie International Edition、AIChE Journal等期刊发表SCI论文24篇，申请专利19件，实现成果转化一项。本项目为从廉价生物质资源到芳香化学品的高值化转化提供了新思路，同时为拓展过渡金属催化剂在涉氢反应中应用提供重要理论支撑。