Xu Leitao, Huang Zhifeng, Yang Ming, Wu Jingcheng, Chen Wei, Wu Yandong, Pan Yuping, Lu Yuxuan, Zou Yuqin, Wang Shuangyin
State Key Laboratory of Chem/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, China.
Angew Chem Int Ed Engl. 2022 Nov 7;61(45):e202210123. doi: 10.1002/anie.202210123. Epub 2022 Sep 29.
Selective electrocatalytic oxidation of alcohols to value-added aldehydes has attracted increasing attention. However, due to its higher reactivity than alcohol, the aldehyde is easily over-oxidized to acid in alkaline electrolytes. Herein we realize the selective electrooxidation of alcohol to aldehyde on NiO by tuning the local microenvironment to salt out the aldehyde from the reaction system. The origin of the high selectivity was found to be the inhibition of the hydration of aldehydes, which is the result of the decreased alkalinity and the increased cation and substrate concentration. This strategy could salt out the aldehyde at the gas|electrolyte interface from the electrooxidation of alcohol with 100 % selectivity and be easily extended to other selective oxidation reactions, such as 5-hydroxymethyl furfural (HMF) to 2,5-furandicarboxaldehyde (DFF) and amine to an imine.
将醇选择性电催化氧化为高附加值醛类已引起越来越多的关注。然而，由于醛比醇具有更高的反应活性，在碱性电解质中醛很容易过度氧化成酸。在此，我们通过调节局部微环境，使醛从反应体系中盐析出来，从而实现了在NiO上醇到醛的选择性电氧化。发现高选择性的根源在于对醛水合作用的抑制，这是碱度降低以及阳离子和底物浓度增加的结果。该策略能够以100%的选择性使醛在气|电解质界面处从醇的电氧化反应中盐析出来，并且易于扩展到其他选择性氧化反应，如5-羟甲基糠醛（HMF）到2,5-呋喃二甲醛（DFF）以及胺到亚胺的反应。
