Two-Dimensional Metastable-Phase Nickel Hexagonal Nanosheets for Highly-Performance Electrochemical Acetone Hydrogenation.

Electrocatalytic acetone hydrogenation into high-value alcohols offers a sustainable alternative to thermal methods. However, developing non-noble metal catalysts with superior performance for electrocatalytic acetone hydrogenation remains challenging. Two-dimensional non-noble metal structure with metastable-phase active sites is promising due to its high-energy structure and unique electronic environment. However, its precise synthesis remains a great challenge. In this work, we report a two-dimensional metastable hexagonal close-packed phase nickel nanosheets (hcp Ni NSs) with a space group of P63/mmc. In the electrocatalytic acetone hydrogenation, it achieves 95.0 % acetone conversion with 100 % isopropanol selectivity. Notably, in the scale-up experiment, the hcp Ni NSs also exhibit 11.51 g gcat-1 h-1 isopropanol production rate at a current density of -250 mA cm-2. Furthermore, this catalyst is widely applicable to various carbonyl compounds. Mechanism study shows that hcp Ni NSs enable strong acetone adsorption and rapid isopropanol desorption.