Abstract
As cathodes,iron-series(Fe,Co,Ni)clusters supported by carbon materials exhibit outstanding electrocat-alytic reduction activities in many electrocatalytic applications.To date,this general characteristic of iron-series clusters that should be related to the inherent attributes of these electrodes has not been fully un-derstood from the perspectives of thermodynamics and electronic structure alone.Electron transport is a necessary process in electrocatalysis,and therefore,the study of the change of the electronic state in elec-tron transport is beneficial for understanding this general characteristic of iron-series cluster catalysts.In this work,the electron transport properties,including the conductivity and transport spin-polarization at the Ni-cluster/graphene interface are carefully investigated as an example of carbon-supported iron-series electrodes.Using first-principles calculations within the framework of the nonequilibrium Green's func-tion density functional theory(NEGF-DFT),we reveal that the electronic transport states of the coupled Ni-cluster/graphene are strongly changed compared to those of their isolated Ni-cluster and graphene component.It is found that graphene dominates the overall conductivity of the interface,while the mor-phology of Ni-clusters controls the spin polarization efficiency.High spin polarization can lead to the self-excitation effect of the electrons that raises the energy of the electronic system,improves the ther-modynamics of the reduction reaction and promotes catalytic activity.Our work hints that iron-series elements(Fe,Co,Ni)based electrodes may generally show transport polarization that is likely to give rise to a high electrocatalytic reduction activity and such transport polarizability can be used as a new factor in the further exploration and design for electrocatalytic materials.
基金项目
111 Project in China(B20029)
Fundamental Research Funds for the Central Universities(N2007011)
Major Research and Development Project of Yunnan Province,China(2018ZE001)
Major Research and Development Project of Yunnan Province,China(202002AB080001-1)
NETL
NSTL
维普
万方数据