Preparation Of Self-template Electrode For Nitrobenzene Reduction And 5-Hydroxymethylfurfural Oxidation In Aqueous Medium

Aniline and 2,5-furandicarboxylic acid are high-value precursors and intermediates for the production of drugs and biodegradable plastics.ever The electrocatalytic reduction of nitroaromatics(NO-RR)and oxidation of5-hydroxymethylfurfural oxidation(HMFOR)using water as a sustainable hydrogen/oxygen source can achieve the green controlled synthesis of functionalized aniline and 2,5-furandicarboxylic acid under mild conditions.However,developing high-efficiency,low-cost electrocatalysts and gaining a deeper understanding of the highly selective conversion mechanism of NO-RR and HMFOR remain challenging.Therefore,this work focuses on the design and development of new efficient mesh ultra-thin nanosheets transition metal catalyst and other materials,and the study of the morphological characteristics of electrocatalysts for high selectivity synthesis of higher value-added products.In this paper,transition metal-based catalysts were constructed for NO-RR and HMFOR by in situ self-template strategy.The details are as follows:(1)Self-supported layered nanosheets(Co9S8/Ni3S2-NF)with a high-density Co9S8/Ni3S2 heterojunction were prepared via an in situ self-template strategy.With combined advantages of high-loading,high surface exposure,good conductivity and unique electronic structure of the Co9S8/Ni3S2 interfaces,the as-prepared Co9S8/Ni3S2-NF exhibited excellent electrocatalytic NO-RR performance,including up to 99.0% conversion and 96.0% selectivity towards aniline(Ph NH2),and outstanding functional group tolerance.Mechanistic investigations and theoretical calculations revealed that electron transfer from Ni3S2 to Co9S8 facilitated the co-adsorption of H2 O and nitrobenzene(Ph NO2)molecules at the interfacial sites,promoted the formation of active hydrogen and subsequent reduction of nitrobenzene.Additionally,the interfacial charge transfer broke the symmetry of two active Co sites at the Co9S8/Ni3S2 interface,which markedly reduced energy barrier for the reduction of nitrobenzene to aniline.(2)The single-atom Ru,highly doped into a Ni O nanoarray to form a self-supported electrode(Ru-Ni O/CC),was prepared by a hydrothermal method and an anodic electrodeposition method.It was used for alkaline water HMFOR,displaying high performance with a 5-hydroxymethylfurfural(HMF)conversion(Con.)as high as 99.7%.The selectivity of 5-furanediformic acid(FDCA)(Sel.)was about 100.0%,and the Faraday efficiency(FE)was 99.7%.The results expose that the Ni O-based catalyst mainly produces FDCA via preferential oxidation of the aldehyde group.The electron transfer from Ni to Ru through interfacial redistribution was beneficial to the adsorption of H2 O and HMF,and promoted the formation of OH*and further dehydrogenation of HMF.In addition,the doping effect was able to effectively reduce the adsorption energy barrier of reaction intermediates at the active site.