Optimization of Electrochemical Reduction of Biomass Derived 5-Hydroxymethylfurfural (HMF): A Volcano Plot and Bimetallic Catalysts

Graphical Volcano plots are highly effective for understanding catalyst mechanisms and rational designing high-performance catalysts, particularly across different metals. However, the understanding of the relationship between different metals and their reaction mechanisms in 5-Hydroxymethylfurfural (HMF) reduction reactions is still limited. In this study, we explore the Gibbs free diagram of HMF reduction reactions on different metal surfaces and construct a volcano plot that connects HMF adsorption energy with the energy barriers of the rate-determining step. This provides a deeper understanding of HMFRR. Our theoretical findings align well with experimental results. Furthermore, we selectively constructed an AgPb bimetal interface based on our volcano plot, which boosted the catalyst activity. DFT calculations revealed that the AgPb bimetal surface effectively adjusts HMF adsorption energy and reduces energy barriers, suggesting that rational designing bimetal catalysts based on volcano plots is efficient. 2,5-bis(hydroxymethyl)furan (BHMF) derived from 5-Hydroxymethylfurfural (HMF) through a hydrogenation process has extensive applications in the production of resins, polymers, and artificial fibers. However, screening out the candidate and then modulating the active site to optimize the catalyst for high yield of BHMF are currently insufficient. In this study, Gibbs free energy diagrams of the reduction of HMF on 13 metals were presented, along with the identification of the rate-determining step (RDS) with the highest reaction barrier for each metal. We attempted to construct a volcano plot for HMFRR reaction. Additionally, a strategy was proposed to adjust the reaction barriers of RDS by combining two appropriate metals. Further experiments confirmed that Pb with the lowest energy barrier exhibited the highest HMF conversion (BHMF selectivity) among single metals. The modified catalyst by doping Ag on Pb, further boosted the HMF conversion (BHMF selectivity) from 42.1 % (59.4 %) to 80.8 % (80.9 %), respectively. These results provide an approach to rationally design and construct the catalyst system for efficient conversion of HMF.