Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
State Key Laboratory for Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, National Engineering Laboratory for Green Chemical Productions of Alcohols-Ethers-Esters, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China.
Proc Natl Acad Sci U S A. 2022 Aug 23;119(34):e2206399119. doi: 10.1073/pnas.2206399119. Epub 2022 Aug 19.
Conversion of naturally occurring sugars, the most abundant biomass resources on Earth, to fuels and chemicals provides a sustainable and carbon-neutral alternative to the current fossil resource-based processes. Tungsten-based catalysts (e.g., WO) are efficient for selectively cleaving C-C bonds of sugars to C oxygenate intermediates (e.g., glycolaldehyde) that can serve as platform molecules with high viability and versatility in the synthesis of various chemicals. Such C-C bond cleavage follows a mechanism distinct from the classical retro-aldol condensation. Kinetic, isotope C-labeling, and spectroscopic studies and theoretical calculations, reveal that the reaction proceeds via a surface tridentate complex as the critical intermediate on WO, formed by chelating both α- and β-hydroxyls of sugars, together with the carbonyl group, with two adjacent tungsten atoms (W-O-W) contributing to the β-C-C bond cleavage. This mechanism provides insights into sugar chemistry and enables the rational design of catalytic sites and reaction pathways toward the efficient utilization of sugar-based feedstocks.
将地球上最丰富的生物质资源——天然存在的糖转化为燃料和化学品，为当前基于化石资源的工艺提供了一种可持续且碳中和的替代方案。钨基催化剂（例如 WO）可高效选择性地切开糖的 C-C 键，生成 C 氧化物中间体（例如乙二醇醛），这些中间体可用作平台分子，在合成各种化学品方面具有很高的可行性和多功能性。这种 C-C 键的切开遵循与经典的反醛缩合不同的机制。动力学、同位素 C 标记和光谱研究以及理论计算表明，反应通过表面三齿配合物作为 WO 上的关键中间体进行，该配合物通过螯合糖的α-和β-羟基以及羰基，与两个相邻的钨原子（W-O-W）一起形成，两个相邻的钨原子（W-O-W）共同促进β-C-C 键的切开。该机制深入了解了糖化学，并能够合理设计催化位点和反应途径，以有效地利用基于糖的原料。
