Capturing critical gem-diol intermediates and hydride transfer for anodic hydrogen production from 5-hydroxymethylfurfural

Guodong Fu; Xiaomin Kang; Yan Zhang; Ying Guo; Zhiwei Li; Jianwen Liu; Lei Wang; Jiujun Zhang; Xian-Zhu Fu; Jing-Li Luo

doi:10.1038/s41467-023-43704-2

Capturing critical gem-diol intermediates and hydride transfer for anodic hydrogen production from 5-hydroxymethylfurfural

Nat Commun. 2023 Dec 18;14(1):8395. doi: 10.1038/s41467-023-43704-2.

Authors

Guodong Fu¹, Xiaomin Kang², Yan Zhang³, Ying Guo¹, Zhiwei Li⁴, Jianwen Liu⁵, Lei Wang¹, Jiujun Zhang^{6

7}, Xian-Zhu Fu⁸, Jing-Li Luo⁹

Affiliations

¹ Shenzhen Key Laboratory of Energy Electrocatalytic Materials, Guangdong Research Center for Interfacial Engineering of Functional Materials, College of Materials Science and Engineering, Shenzhen University, 518060, Shenzhen, China.
² School of Mechanical Engineering, University of South China, 421001, Hengyang, Hunan Province, China.
³ Pingshan Translational Medicine Center, Shenzhen Bay Laboratory, 518055, Shenzhen, Guangdong Province, China.
⁴ National Supercomputing Center in Shenzhen, 518055, Shenzhen, China.
⁵ Shenzhen Key Laboratory of Energy Electrocatalytic Materials, Guangdong Research Center for Interfacial Engineering of Functional Materials, College of Materials Science and Engineering, Shenzhen University, 518060, Shenzhen, China. jwliu@szu.edu.cn.
⁶ College of Materials Science and Engineering, Fuzhou University, 350108, Fuzhou, China.
⁷ Institute for Sustainable Energy, College of Science, Shanghai University, 200444, Shanghai, China.
⁸ Shenzhen Key Laboratory of Energy Electrocatalytic Materials, Guangdong Research Center for Interfacial Engineering of Functional Materials, College of Materials Science and Engineering, Shenzhen University, 518060, Shenzhen, China. xz.fu@szu.edu.cn.
⁹ Shenzhen Key Laboratory of Energy Electrocatalytic Materials, Guangdong Research Center for Interfacial Engineering of Functional Materials, College of Materials Science and Engineering, Shenzhen University, 518060, Shenzhen, China. jll@szu.edu.cn.

Abstract

The non-classical anodic H₂ production from 5-hydroxymethylfurfural (HMF) is very appealing for energy-saving H₂ production with value-added chemical conversion due to the low working potential (~0.1 V vs RHE). However, the reaction mechanism is still not clear due to the lack of direct evidence for the critical intermediates. Herein, the detailed mechanisms are explored in-depth using in situ Raman and Infrared spectroscopy, isotope tracking, and density functional theory calculations. The HMF is observed to form two unique inter-convertible gem-diol intermediates in an alkaline medium: 5-(Dihydroxymethyl)furan-2-methanol anion (DHMFM^-) and dianion (DHMFM^2-). The DHMFM^2- is easily oxidized to produce H₂ via H^- transfer, whereas the DHMFM^- is readily oxidized to produce H₂O via H⁺ transfer. The increases in potential considerably facilitate the DHMFM^- oxidation rate, shifting the DHMFM^- ↔ DHMFM^2- equilibrium towards DHMFM^- and therefore diminishing anodic H₂ production until it terminates. This work captures the critical intermediate DHMFM^2- leading to hydrogen production from aldehyde, unraveling a key point for designing higher performing systems.