Cobalt telluride regulated by nickel for efficient electrooxidation of 5-hydroxymethylfurfural.

Ni-doped CoTe nanorods have been prepared for 5-hydroxymethylfurfural oxidation reaction. The doping of Ni facilitates the oxidation of Co2+ to high-valent CoO 2 to achieve efficient electrosynthesis of the valuable 2,5-furandicarboxylic acid. [Display omitted] • A crude nanorod structure CoNiTe was prepared by two-step hydrothermal reactions for HMFOR. • Ni doping modulates the electronic structure of Co and improves the electrocatalytic performance of CoNiTe. • The generation of high-valent cobalt is the key for excellent HMFOR. Replacing the anodic oxygen evolution reaction (OER) in water splitting with 5-hydroxymethylfurfural oxidation reaction (HMFOR) can not only reduce the energy required for hydrogen production but also yield the valuable chemical 2,5-furandicarboxylic acid (FDCA). Co-based catalysts are known to be efficient for HMFOR, with high-valent Co being recognized as the main active component. However, efficiently promoting the oxidation of Co2+ to produce high-valent reactive species remains a challenge. In this study, Ni-doped CoTe (CoNiTe) nanorods were prepared as efficient catalysts for HMFOR, achieving a high HMFOR current density of 65.3 mA cm−2 at 1.50 V. Even after undergoing five successive electrolysis processes, the Faradaic efficiency (FE) remained at approximately 90.7 %, showing robust electrochemical durability. Mechanistic studies indicated that Ni doping changes the electronic configuration of Co, enhancing its charge transfer rate and facilitating the oxidation of Co2+ to high-valent CoO 2 species. This work reveals the effect of Ni doping on the reconfiguration of the active phase during HMFOR. [ABSTRACT FROM AUTHOR]