defense

metastatic colorectal

faradaic efficiency

orr_71065

faradaic

bi te

electrochemical co

orr activity

vomeronasal

catalytic_11883

single atom

single-atom catalysts

privatization

ganoderma

pu-erh

gnrs

enrr

prostate_46495

single-atom_38008

Angewandte Chemie International Edition

The general synthesis and control of the coordination environment of single-atom catalysts (SACs) remains a great challenge. Herein, a general host-guest cooperative protection strategy has been developed to construct SACs by introducing polypyrrole (PPy) into a bimetallic metal-organic framework. As an example, the introduction of Mg2+ in MgNi-MOF-74 extends the distance between adjacent Ni atoms; the PPy guests serve as N source to stabilize the isolated Ni atoms during pyrolysis. As a result, a series of single-atom Ni catalysts (named NiSA -Nx -C) with different N coordination numbers have been fabricated by controlling the pyrolysis temperature. Significantly, the NiSA -N2 -C catalyst, with the lowest N coordination number, achieves high CO Faradaic efficiency (98 %) and turnover frequency (1622 h-1 ), far superior to those of NiSA -N3 -C and NiSA -N4 -C, in electrocatalytic CO2 reduction. Theoretical calculations reveal that the low N coordination number of single-atom Ni sites in NiSA -N2 -C is favorable to the formation of COOH* intermediate and thus accounts for its superior activity.

Regulating the Coordination Environment of MOF‐Templated Single‐Atom Nickel Electrocatalysts for Boosting CO2 Reduction