Asymmetrically Cu-O-Cu Bridged dual-atom sites on bio

Abstract

Theelectrochemicalnitratereductionreaction(NO3RR)isapromisingstrategyfordecentralizedammonia(NH3)productionandenvironmental remediationunder ambient conditions. However, achieving complete eightelectron/nine-proton(8e /9H+)conversionofNO3 oNH3withhighselectivityandefficiencyremainschallengingowingtosluggishNO3 ctivationandcompetingN–uplingsidereactionssuchasN2,N2O,andNOgasevolution.Herein,wereportarationallydesignedCudual-atom(DA)catalystcomposedofasymmetricallycoordinatedCuatomicpairsanchoredonanL-tryptophan-functionalizedFe3O4/α-Fe2O3heterostructure(Cu2/ try-FeOx), synthesizedviaaCO2 laser irradiationmethodinvolvingmulti-stepcontinuous-waveexposure for interfaceengineering. ThehybridCu2/try-FeOx support provides abundantNandOcoordinationsites and enhancedelectronmobility,enablingspatiallyseparatedCuatombyasymmetricallycoordinatedCu–N/Odualsites exhibit synergistic electronic interactions, forming robustDAconfigurations. Insituandex situspectroelectrochemicalanalyses,supportedbytheoreticalcalculations,confirma*NO3→*NO2→*NO→*NHO→*NH2O→*NH3→NH3reactionpathway.Attheoptimalpotential,thetotalFaradaicefficiencytowardNH3andNO2approaches~95%,indicatingeffectivesuppressionofcompetingH2,N2,andN2Oformationandconfirmingahighlyselective8e‒/9H+NO3RRmechanism.Notably,NO3RRtestsusingCu2/try-FeOXachieveahighNH3yieldrateof0.29mmolh 1cm2andamaximumFaradaicefficiencyof88.5%at .2Vvs.RHE.Furthermore,whenintegratedintoaZn–NO3 battery, thecatalystenablesself-poweredNO3 toNH3conversionwithstableoperationover100h.ThisstudypresentsarationalapproachthatintegratesDAsiteengineeringcatalystdesignwithbio-unctionalsupportdesigntoregulateintermediateadsorptionandelectrontransfer,therebyenhancingtheactivityandselectivityforself-poweredmolecularNO3upcyclingtechnologies.