In situ catalytic hydrogenolysis of lignin is an efficient method for lignin valorization. Herein, a novel in situ lignin catalytic hydrogenolysis technique in alkaline aqueous solution over a NiAl alloy catalyst under mild conditions was systematically suited. Ni served as the active phase and could be exposed by etching Al atoms with alkaline aqueous solution. Meanwhile, H₂ resources could be in situ generated and easily arrived at the adjacent exposed Ni sites to be activated. The in situ lignin hydrogenolysis system exhibits attractive depolymerization results under mild conditions, with an 86.8% conversion degree and 18.9 wt % yield of aromatic monomers at 220 °C, much higher than the traditional hydrogenolysis method using a commercial Raney Ni catalyst under high pressure external H₂. The mechanism studies with lignin model compounds suggest that alkaline aqueous solution could promote the cleavage of C–O–C bonds and hinder the hydrogenation of the benzene ring. In addition, a moderate amount of exposed Ni sites as well as rich active hydrogen species are determinant for efficient lignin depolymerization.

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木质素平衡：碱性水溶液中原位催化氢解的新方法

木质素的原位催化氢解是木质素增值的有效方法。在此，系统地适合于在温和条件下在NiAl合金催化剂上的碱性水溶液中在碱水溶液中的新的原位木质素催化氢解技术。Ni用作活性相，并且可以通过用碱性水溶液蚀刻Al原子来暴露。同时，H ₂资源可以原位产生并且容易到达相邻的暴露的Ni位点以被激活。原位木质素氢解系统在温和条件下显示出有吸引力的解聚结果，在220°C下的转化率为86.8％，芳香族单体的收率为18.9 wt％，远高于使用商业阮内镍催化剂在高压外部条件下进行的传统氢解方法。高₂。木质素模型化合物的机理研究表明，碱性水溶液可以促进C–O–C键的裂解并阻碍苯环的氢化。另外，适量的暴露的Ni位以及丰富的活性氢种类是有效的木质素解聚的决定因素。