Synergistic Pd3Pt1 bimetallene for energy-efficient biomass conversion

The sustainable production of fuels and value-added chemicals from biomass is a cornerstone of the future bioeconomy. 5-hydroxymethylfurfural (HMF), a platform molecule derived from lignocellulosic biomass, holds immense promise for replacing petroleum-derived building blocks. Its selective hydrogenation to 2,5-dihydroxymethylfuran (DHMF), a crucial precursor for pharmaceuticals, nucleoside analogs, and specialty polymers, is of particular interest. However, conventional thermocatalytic HMF hydrogenation often necessitates harsh conditions (high temperatures and pressures), leading to substantial energy consumption and process intensification challenges. 

A recent breakthrough, published in Chinese Journal of Catalysis, presents a compelling alternative: electrochemical hydrogenation (ECH) at ambient conditions. A research team led by Prof. Yu Chen from Shaanxi Normal University, China, has developed a highly alloyed Pd₃Pt₁ bimetallene (Pd₃Pt₁ BML) that enables the energy-saving ECH of HMF to DHMF.

This novel Pd₃Pt₁ BML synthesized via a facile galvanic displacement reaction, exhibits a unique two-dimensional metallene structure. This morphology, combined with the atomically-dispersed Pt within the Pd lattice, provide distinct catalytic advantages. The catalyst demonstrates a remarkable Faradaic efficiency exceeding 93% and a DHMF selectivity surpassing 66% under mild conditions.

The exceptional performance of the Pd₃Pt₁ BML stems from a synergistic interplay of geometric and electronic effects. In-situ Raman spectroscopy provides compelling evidence of the weakened HMF adsorption on Pd sites. Density Functional Theory (DFT) calculations corroborate this observation, highlighting the critical role of Pt in promoting hydrogen spillover and facilitating the hydrogenation process. The atomically dispersed Pt not only mitigates catalyst poisoning by reducing the binding strength of HMF on Pd, but also serves as a source of abundant active hydrogen species, thereby accelerating the overall conversion.

A key innovation of this work is the strategic coupling of HMF ECH (at the cathode) with the formic acid oxidation reaction (FAOR) at the anode. This paired electrolysis approach circumvents the kinetically sluggish oxygen evolution reaction (OER), which typically limits the efficiency of electrochemical systems. The assembled Pd₃Pt₁ BML||Pd₃Pt₁ BML electrolyzer system reaches a current density of 10 mA cm^-2 at a remarkably low cell voltage of only 0.72 V for HMF ECH. This presents a substantial voltage reduction of nearly 1 V compared to analogous HMF ECH systems coupled with OER, translating to a significant decrease in energy consumption. The synergistic ensemble and electronic effects of Pd-Pt structure are central to achieve both high catalytic activity and excellent selectivity toward DHMF production. The results were published in Chinese Journal of Catalysis (DOI: 10.1016/S1872-2067(24)60189-0).

About the Journal

Chinese Journal of Catalysis is co-sponsored by Dalian Institute of Chemical Physics, Chinese Academy of Sciences and Chinese Chemical Society, and it is currently published by Elsevier group. This monthly journal publishes in English timely contributions of original and rigorously reviewed manuscripts covering all areas of catalysis. The journal publishes Reviews, Accounts, Communications, Articles, Highlights, Perspectives, and Viewpoints of highly scientific values that help understanding and defining of new concepts in both fundamental issues and practical applications of catalysis. Chinese Journal of Catalysis ranks among the top one journals in Applied Chemistry with a current SCI impact factor of 15.7. The Editors-in-Chief are Profs. Can Li and Tao Zhang.

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