Gadolinium Changes the Local Electron Densities of Nickel 3d Orbitals for Efficient Electrocatalytic CO2 Reduction

Generally, in terms of electrocatalytic CO2 reduction, single-atom catalysts show high selectivities yet low current densities whereas conventional nanoparticle catalysts exhibit relatively high current densities but low selectivities. This work combines the advantages of the two classes of catalysts by constructing a Ni-Gd-N-doped carbon black electrocatalyst within which Ni-I active sites are exposed outside the carbon layers and Ni nanoparticles are encapsulated inside the carbon layers. The Gd atoms can not only influence the local electron densities of Ni 3d orbitals, thus strengthening the electronic activity, but also tailor the sizes of the Ni nanoparticles, thereby minimizing the activity toward hydrogen evolution. Accordingly, this electrocatalyst yields both a high CO faradaic efficiency (97 %) and a large current density (308 mA cm(-2)), alongside an outstanding stability (100 h).

Automated summary

This study combines the advantages of single-atom catalysts and conventional nanoparticle catalysts to improve the selectivity and current density of CO2 reduction. The developed Ni-Gd-N-doped carbon black electrocatalyst exhibits a high CO faradaic efficiency and a large current density, with outstanding stability.