Phase transition induced hydrogen activation for enhanced furfural reductive amination over a CoCu bimetallic catalyst

Abstract

The synthesis of primary amines from renewable biomass and its derivatives through reductive amination has garnered significant attention. How to construct efficient non-noble-metal catalysts that enable low-temperature catalysis still remains challenging. Herein, we report a Cu-doped Co@CoO_x heterostructure catalyst that features structural Co–CoCuO_x bifunctional sites, which enable room temperature reductive amination of various aldehydes with 1.57–45 times higher efficiency than Co@CoO_x, outperforming many reported non-noble and even noble metal catalysts. Experiments and DFT calculations indicate that Cu doping leads to a phase transition of Co from hcp to fcc, while electrons are transferred from Cu to Co, forming a dual active site with electron-rich Co closely interacting with CoCuO_x. These electron-rich Co sites demonstrate excellent activity in the activation and dissociation of hydrogen, while the CuO_x component facilitates hydrogen spillover at the CoCuO_x interface, thus resulting in a highly efficient cooperative effect for the furfural (FAL) reductive amination. This work provides general guidance for the rational design of high-performance reductive amination catalysts for biomass upgrading.