Chalcogen heteroatoms doped nickel-nitrogen-carbon single-atom catalysts with asymmetric coordination for efficient electrochemical CO2 reduction
The electronic configuration of central metal atoms in single-atom catalysts(SACs)is pivotal in electrochemical CO2 reduction reaction(eCO2RR).Herein,chalcogen heteroatoms(e.g.,S,Se,and Te)were incorporated into the symmetric nickel-nitrogen-carbon(Ni-N4-C)configuration to obtain Ni-X-N3-C(X:S,Se,and Te)SACs with asymmetric coordination presented for central Ni atoms.Among these obtained Ni-X-N3-C(X:S,Se,and Te)SACs,Ni-Se-N3-C exhibited superior eCO2RR ac-tivity,with CO selectivity reaching～98％at-0.70 V versus reversible hydrogen electrode(RHE).The Zn-CO2 battery integrated with Ni-Se-N3-C as cathode and Zn foil as anode achieved a peak power density of 1.82 mW cm-2 and maintained remarkable rechargeable stability over 20 h.In-situ spectral investigations and theoretical calculations demonstrated that the chalcogen heteroatoms doped into the Ni-N4-C configuration would break coordination symmetry and trigger charge redis-tribution,and then regulate the intermediate behaviors and thermodynamic reaction pathways for eCO2RR.Especially,for Ni-Se-N3-C,the introduced Se atoms could significantly raise the d-band center of central Ni atoms and thus remarkably lower the energy barrier for the rate-determining step of*COOH formation,contributing to the promising eCO2RR performance for high selectivity CO production by competing with hydrogen evolution reaction.
Electrochemical CO2 reduction reactionChalcogen heteroatomsSingle-atom catalystsAsymmetric coordinationCO production
万方数据
