Catalytic hydrodeoxygenation (HDO) is one of the most promising strategies to transform oxygen-rich biomass derivatives into high value-added chemicals and fuels, but highly challenging due to the lack of highly efficient nonprecious metal catalysts. Herein, we report for the first time of a facile synthetic approach to controllably fabricate well-defined Ni-Co alloy NPs confined on the tip of N-CNTs as HDO catalyst. The resultant Ni-Co alloy catalyst possesses outstanding HDO performance towards biomass-derived vanillin into 2-methoxy-4-methylphenol in water with 100% conversion efficiency and selectivity under mild reaction conditions, surpassing the reported high performance nonprecious HDO catalysts. Impressively, our experimental results also unveil that the Ni-Co alloy catalyst can be generically applied to catalyze HDO of vanillin derivatives and other aromatic aldehydes in water with 100% conversion efficiency and over 90% selectivity. Importantly, our DFT calculations and experimental results confirm that the achieved outstanding HDO catalytic performance is due to the greatly promoted selective adsorption and activation of C=O, and desorption of the activated hydrogen species by the synergism of the alloyed Ni-Co NPs. The findings of this work affords a new strategy to design and develop efficient transition metal-based catalysts for HDO reactions in water.

催化加氢脱氧 (HDO) 是将富氧生物质衍生物转化为高附加值化学品和燃料的最有前途的策略之一，但由于缺乏高效的非贵金属催化剂而极具挑战性。在此，我们首次报道了一种简便的合成方法，可以可控地制造限定在 N-CNT 尖端的明确定义的 Ni-Co 合金 NP 作为 HDO 催化剂。所得Ni-Co合金催化剂在温和的反应条件下对生物质衍生的香草醛在水中转化为2-甲氧基-4-甲基苯酚具有出色的HDO性能，转化效率和选择性为100%，超过了报道的高性能非贵重HDO催化剂。令人印象深刻的是，我们的实验结果还表明，Ni-Co 合金催化剂可普遍应用于催化水中香兰素衍生物和其他芳香醛的 HDO，转化效率为 100%，选择性超过 90%。重要的是，我们的 DFT 计算和实验结果证实，所实现的出色的 HDO 催化性能是由于合金化 Ni-Co NP 的协同作用极大地促进了 C=O 的选择性吸附和活化，以及活化氢物质的解吸。这项工作的发现为设计和开发用于水中 HDO 反应的高效过渡金属基催化剂提供了一种新策略。我们的 DFT 计算和实验结果证实，所实现的出色的 HDO 催化性能是由于合金化 Ni-Co NP 的协同作用大大促进了 C=O 的选择性吸附和活化，以及活性氢物质的解吸。这项工作的发现为设计和开发用于水中 HDO 反应的高效过渡金属基催化剂提供了一种新策略。我们的 DFT 计算和实验结果证实，所实现的出色的 HDO 催化性能是由于合金化 Ni-Co NP 的协同作用大大促进了 C=O 的选择性吸附和活化，以及活性氢物质的解吸。这项工作的发现为设计和开发用于水中 HDO 反应的高效过渡金属基催化剂提供了一种新策略。