The identification of dual active routes for highly efficient furfural oxidation reaction coupling with hydrogen production over Re modulated Co(OH)2/CC

Abstract

It is of great significance and challenge to tune the active sites of two-dimensional materials and identify the exclusive active sites for separate reaction toward hydrogen evolution reaction (HER) coupled with electrochemical oxidation (ECO) reaction. Herein, Re was introduced to tune d band charge density of Co, which reduced the energy barrier of water splitting for HER. Meanwhile, the abundant oxygen vacancies (Ov) caused by Re introduction resulted in a new reaction route for furfural oxidation reaction (FOR). That is, the adsorbed OH− on Ov accelerates the dehydrogenation of Co(OH)O, and the active site further promotes the nucleophile dehydrogenation, thus improving the catalytic performance of FOR. In conclusion, Re-Co(OH)2/CC with Re modified Co-centered sites displays dual active routes, which simultaneously enhance FOR and HER with a cell voltage (1.36 V) at 10 mA cm−2, surpassing the most two-dimensional transition-metal hydroxides (2D TMHs) results reported as we known. This work provides new insights into the modulation of Co electronic structure and Ov concentration, which results in enhanced bifunctional electrocatalytic reactions.