Electrocatalytic oxidation of 5-hydroxymethylfurfural (HMFOR) is advantageous for the efficient upgrading of biomass-derived platform chemicals. Additionally, it can save energy in hydrogen (H₂) production by replacing the conventional oxygen evolution reaction. The surface reconstruction behavior on transition-metal-based materials is closely correlated with their HMFOR performance. Thus, one of the key challenges for designing efficient electrocatalysts lies in promoting the reconstruction and understanding the mechanism behind it. Herein, we report an amorphous CoNi sulfide with abundant sulfur vacancies that promote the surface reconstruction of active sites, thereby improving the HMFOR performance. The CoNiS-A@NF delivers efficient HMF upgrading with high conversion (98.5%), selective 2,5-furandicarboxylic acid production with a yield, and a Faradaic efficiency of 97%. The sulfur-deficient structure contributes to the interaction with OH^–, which provides the driving force for surface reconstruction. Time-dependent operando Raman results verify a high rate of surface reconstruction on the CoNiS-A@NF surface, with the reconstruction rate even surpassing the consumption rate in the concentrated HMF electrolyte. When acting as a bifunctional electrode in a flow-mode electrolyzer, the CoNiS-A@NF exhibits an energy saving of 15.9% for simultaneously producing H₂ and 2,5-furandicarboxylic acid. The present work tracks the structural evolution of an amorphous surface and reveals the correlation with electrocatalytic performance, providing guidelines for designing efficient catalysts applied in sustainable energy conversions.

中文翻译：

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在无定形表面快速重构促进 5-羟甲基糠醛辅助制氢

5-羟甲基糠醛 （HMFOR） 的电催化氧化有利于生物质衍生平台化学品的高效升级。此外，它可以通过替代传统的析氧反应来节省氢气 （H₂） 生产的能源。过渡金属基材料的表面重建行为与其 HMFOR 性能密切相关。因此，设计高效电催化剂的关键挑战之一在于促进重构并理解其背后的机制。在此，我们报道了一种具有丰富硫空位的无定形 CoNi 硫化物，可促进活性位点的表面重建，从而提高 HMFOR 的性能。CoNiS-A@NF 提供高效的 HMF 升级、高转化率 （98.5%）、选择性 2,5-呋喃二羧酸生产（产率）和 97% 的法拉第效率。缺硫结构有助于与 OH^– 相互作用，从而为表面重建提供动力。瞬态原位拉曼结果验证了 CoNiS-A@NF 表面的高表面重建率，重建率甚至超过了浓 HMF 电解质中的消耗率。当在流动模式电解槽中用作双功能电极时，CoNiS-A@NF 可同时生产 H₂ 和 2,5-呋喃二羧酸，可节省 15.9% 的能源。目前的工作跟踪了无定形表面的结构演变，并揭示了与电催化性能的相关性，为设计应用于可持续能源转换的高效催化剂提供了指导。