Electrochemiluminescent Characterization Of Surface Electronic Structure On Highly Dispersed Catalysts

Structral adjustment is vital to high performance catalysts.In recent yeas,researchers prepared nano-structure catalysts and single atom catalysts by tuning valance state composition,constructing coordinate site and altering electronic spin distribution persuing for an explanation of mechanism for enhanced chemical behavior or an instruction to design novel catalysts.Layered Double Hydroxides,as LDHs,feature orderly assembled structure and tunable composition,which can act as support for highly dispersed noble metal catalysts with broad applications.This work was about nodifying localized electronic structure of noble metal loaded LDHs,aiming at developing an electrochemiluminesce(ECL)method for characterization of electronic structure on LDHs supported higly dispersed noble metal particles by Luminol system.Electronic Metal-Support Interaction(EMSI)phenomenon and spin-state theory were combined with ECL tu study microenvironment of catalysts probing relationship between electronic structure and electrochemical performance and revealling mechanism.In our first part,EMSI between Au NPs and alkali etched CoAl-LDH was confirmed that surface defects altered localized surface electron structure and valance state distribution.Hence,promoted EMSI led to promoted electron transfer rate on Au/LDH and more ROS generation,which resulted in ECL amplification.It was also noticed that over etched CoAl-LDH suffered weakened EMSI due to a disordered chemical structure and ECL signal declined.This phenomenon revealed a relationship between ECL intensity and EMSI by illustrating properties of Au NPs on varied support catalysts.This suggested a potential for ECL to characterize electronic structure.In our second part,we used the model catalyst RuSA/NiFe-LDH,with sinle atom Ruand valance state tunable elements NiFe-LDH.Ruwith strong electronegativity influenced spin state density of LDHs support by oxygen bridged Ru-O-Fe structure.Valance state evolution of intrinsic NiFe-LDH and ROS accumulation were analyzed by a\ECL signal and structural characterization.ECL behaviors indicated that inherent catalytical activity of NiFe-LDH was boosted by single atom Ru.We provided a new sight into understanding structure-activity relationship and a new mechanism for ECL by single atom catalysts.In this work,traditional highly dispersed noble metal catalysts were used to study cataytical performance and electronic structure.ECL method was carried out to charactereize electronic structure and to obtain a better understand of mechanism for electrochemical catalysts.