Constructing Ultrafine Ru Nanoclusters via a Dual-Confinement Strategy: Synergizing Hierarchical Pores and Electronic Modulation for Efficient Lignin Hydrogenolysis

en This link goes to a English section zh This link goes to a Chinese section Lignin hydrogenolysis is a promising route to separable aromatic monomers, yet practical upgrading is still hindered by macromolecular mass-transfer limitations and the aggregation/deactivation of metal sites. Herein, we propose a “dual-confinement” strategy to construct ultrafine Ru nanoclusters supported on lignin-based N-doped hierarchical porous carbon, utilizing lignin itself as the precursor. This architecture synergizes physical confinement via a potassium oxalate-activated hierarchical pore network, with chemical confinement through in situ nitrogen doping that anchors Ru species. The resulting catalyst exhibits exceptional performance, achieving 99.8% conversion of model compounds and a remarkable 40.6 wt% yield of aromatic monomers from isolated birch lignin under mild conditions. The exceptional catalytic performance originates from synergistic dual-confinement effects, in which hierarchical porosity enables efficient mass transfer of lignin substrates, whereas N-doping provides robust chemical anchoring of the ultrafine Ru active sites. Density functional theory calculations further elucidate that electronic modulation at the Ru–N interface significantly lowers the activation energy for C–O bond cleavage. This work demonstrates a high-efficiency depolymerization protocol and establishes a theoretical framework for designing robust dual-confined catalysts in macromolecular biomass conversion. 摘要 en This link goes to a English section zh This link goes to a Chinese section 木质素氢解是制备可分离芳香单体的重要途径,然而其实际转化升级仍受制于大分子传质阻力以及金属活性位点团聚与失活等问题。针对上述瓶颈,本研究提出一种“双重限域”策略,以木质素自身为前驱体,构建了负载于木质素基氮掺杂分级多孔碳上的超细Ru纳米团簇。该体系通过草酸钾活化构筑的分级孔网络实现物理限域,并借助原位氮掺杂对Ru物种的锚定实现化学限域,二者协同强化了活性位点的稳定性与可及性。所制备催化剂展现出优异的催化性能,温和条件下对模型化合物的转化率达99.8%,桦木木质素获得高达40.6 wt%的芳香单体产率。上述卓越性能源于双重限域的协同效应:分级孔隙结构促进了木质素大分子底物的高效传质,氮掺杂位点则为超细Ru活性中心提供了牢固的化学锚定。密度泛函理论 (DFT)计算进一步表明,Ru–N界面处的电子调控显著降低了C–O键断裂的活化能。本研究提供了一种高效的木质素解聚方案,并为大分子生物质转化中限域催化剂的设计奠定了理论基础。