Ultrathin two-dimensional mesoporous holmium oxide nanosheet stabilized copper nanoparticle for stable and efficiency electrocatalytic semi-hydrogenation of acetylene

Abstract

The removal of acetylene (C2H2) from ethylene (C2H4) is a critical step in the production of high-purity C2H4. Due to the low reaction temperature and energy consumption and high selectivity of C2H4, the electrocatalytic semi-hydrogenation of C2H2 is the ideal method for removing C2H2. Herein, the ultrathin two-dimensional (2D) mesoporous holmium oxide nanosheet stabilized copper nanoparticle (Cu/Ho2O3) for stable and efficiency electrocatalytic semi-hydrogenation of C2H2 was prepared through a simple and one step high-temperature calcination-reduction method. The ultra-thin two-dimensional mesoporous structure of holmium oxide creates abundant coordination defects to improve the Faraday efficiency and the durability of copper nanoparticle for catalyzing the semi-hydrogenation of C2H2. The as-prepared Cu/Ho2O3 achieved the C2H4 selectivity of 99.6% and Faradaic efficiency of 98.1%, because the presence of oxygen vacancies is conducive to form electron-rich Cu nanoparticle, thereby promoting the adsorption of electrophilic C2H2 and the desorption of nucleophilic C2H4. Meanwhile the holmium oxide nanosheet with unsaturated coordination sites can stabilize the Cu nanoparticle, and the Faradaic efficiency and current density remains stable for more than 600 minutes. This work offers a promising design strategy for the stable and efficiency electrocatalyst for semi-hydrogenation reaction of C2H2 to C2H4.