Recent advances in electrochemical synthesis of high-value derivatives from 5-hydroxymethylfurfural

With application of renewable energy and mild synthesis condition, the electrochemical conversion of 5-hydroxymethylfurfural (HMF) into high-value chemicals via electrocatalytic oxidation/reduction reaction recently draws more attentions. For example, the oxidation products of HMF such as 2,5-furandicarboxylic acid (FDCA), 2,5-dihydroxymethyifuran (HMFCA), 2,5-diformylfuran (DFF), and maleic acid (MA) are important industrial products. The reduction products of HMF are also widely used, 2,5-dimethylfuran (DMF), 2,5-dihydroxymethyifuran (DHMF), 2,5-dihydroxy methyl tetrahydrofuran (DHMTHF), 2,5-hexanedione (HD), and 5,5 '-bis (hydroxymethyl) hydrofuroin (BHH) have been reported and attracted widespread attention. However, some problems including uncertain mechanism, excessive activation power, low catalytic activity, and high barrier are existed and need to be urgently solved. This review aims to provide a summary of advances in electrochemical synthesis of high-value derivatives from HMF. Firstly, the concept and reaction mechanisms for electrocatalytic oxidation/ reduction of HMF are introduced detailly. Secondly, different kinds of electrocatalysts for the electrochemical conversion of HMF and their structure-activity relationship are systematically investigated. Moreover, the potential challenges and prospects for electrochemical conversion of HMF are also proposed. This work provides an important guidance for constructing efficient electrocatalysts toward electrochemical conversion of HMF.