Achieving highly efficient CO₂ to CO electroreduction exceeding 300 mA cm⁻² with single-atom nickel electrocatalysts

Abstract

A high CO2 to CO electroreduction rate exceeding 300 mA cm−2 was achieved with single atom nickel and nitrogen doped three-dimensional porous carbon electrocatalysts.

Understanding the Origin of Highly Selective CO2 Electroreduction to CO on Ni,N‐doped Carbon Catalysts

“…This high selectivity is in agreement with many recent literature reports of selective CO production in Ni,N-doped carbon materials (summary of past reported Ni-N-C catalysts in SI Table 2). [13][14][15][16][17][18][19][20][21] Thep artial current density towards CO increases with applied electrode potential and reaches 21 mA cm À2 at À1.1 Vvs. RHE before the onset of hydrogen evolution which results in aplateau in j CO and an increase of j tot to 40 mA cm À2 at À1.3 Vv s. RHE ( Figure 3B).…”

“…TheN i-N-C for CO 2 Rr eports have,h owever, varied in their assignment of Ni oxidation state,c oordination number, and bonding environment, and have not shown conclusive evidence of nitrogen-nickel bonding. [13][14][15][16][17][18][19][20][21] In addition, previous reports have focused far more on characterizing Ni in the single atom form with less attention to the role of Ni aggregates in controlling the catalytic performance of Ni-N-C materials.T hus,o pen challenges remain in confirming that nickel-nitrogen bonding occurs in these materials,a nd in conclusively attributing catalytic activity to these dispersed Ni species.…”

Understanding the Origin of Highly Selective CO2 Electroreduction to CO on Ni,N‐doped Carbon Catalysts

“…In the CO 2 electroreduction literature, highly selective CO 2 reduction to CO has been reported by many groups for both N‐C and M‐N‐C catalysts, with M=Fe, Co, and Ni showing the most promising performance . Among these materials, Ni‐N‐C has been reported by many groups to have Faradaic efficiencies toward CO exceeding 90 % . The proposed active site structure for Ni‐N‐C is atomically dispersed Ni‐N x sites, a hypothesis that has been made based on evidence from electron microscopy, hard X‐ray absorption spectroscopy, and density functional theory .…”

Nanocatalysts Containing Direct Electron Transfer-Capable Oxidoreductases: Recent Advances and Applications

“…CO may be readily used for the various synthetic processes for the production of hydrocarbons using Fischer-Tropsch [114] or for the production of acetic acid using Monsanto processes [115]. Though CO 2 is generally abundant, it is difficult convert those gases to CO at high yields without many additional byproducts [116]. For this reason, nanocatalytic systems could be designed containing enzyme-metallic nanoparticle conjugates, which could produce CO from CO 2 .…”

“…The standard redox potentials at pH 7.0 and 25 • C for some catalytically relevant half-reactions are given in Figure 10 [90,126]. that enzymatic activity dependence on pH during heterogeneous catalysis could be altered by rational engineering of the surface charge of the enzyme carrier [116]. However, we would like to point out that all of the above-mentioned approaches could affect the DET capability of the oxidoreductase, and thus should be used with additional care.…”