Partially Nitrided Ni Nanoclusters Achieve Energy‐Efficient Electrocatalytic CO₂ Reduction to CO at Ultralow Overpotential

Abstract

Electrocatalytic CO2 reduction reaction (CO2RR) offers a promising strategy to lower CO2 emission while producing value‐added chemicals. A great challenge facing CO2RR is how to improve energy efficiency by reducing overpotentials. Herein, partially nitrided Ni nanoclusters (NiNx) immobilized on N‐doped carbon nanotubes (NCNT) for CO2RR are reported, which achieves the lowest onset overpotential of 16 mV for CO2‐to‐CO and the highest cathode energy efficiency of 86.9% with CO Faraday efficiency >99.0% to date. Interestingly, NiNx/NCNT affords a CO generation rate of 43.0 mol g−1 h−1 at a low potential of −0.572 V (vs RHE). DFT calculations reveal that the NiNx nanoclusters favor *COOH formation with lower Gibbs free energy than isolated Ni single‐atom, hence lowering CO2RR overpotential. As NiNx/NCNT is applied to a membrane electrode assembly system coupled with oxygen evolution reaction, a cell voltage of only 2.13 V is required to reach 100 mA cm−2, with total energy efficiency of 62.2%.

Laser-controlled tandem catalytic sites of CuNi alloys with ampere-level electrocatalytic nitrate-to-ammonia reduction activities for Zn–nitrate batteries

“…14 Nickel (Ni) is a VIII group element with great ability of O–H activation and strong H* adsorption ability, which is expected to be an ideal site to provide sufficient H* without excessive hydrogen evolution reaction (HER). 15,16 Thus, introducing Ni sites into Cu-based catalysts might create tandem site configuration for Cu-based materials and significantly improve their NIRR performance. Currently, the performance enhancement based on the reported catalysts of Cu–Ni tandem sites is ungratified, and the interaction of tandem sites and their behaviors in catalytic processes remains questionable.…”

Temperature‐Induced Low‐Coordinate Ni Single‐Atom Catalyst for Boosted CO2 Electroreduction Activity

“…, which are attributed to the unpaired electrons trapped by surface defects and vacancies. [22] Moreover, the EPR peak intensity of Ni-Nx-C increases gradually with increase of temperature, demonstrating that more N vacancies are generated in Ni-Nx-C catalysts. Based on the above results, it is reasonable to believe that the ECR performance of Ni-Nx-C catalysts may be related to the coordination environment of Ni centers.…”

Boron‐Doped Nickel–Nitrogen–Carbon Single‐Atom Catalyst for Boosting Electrochemical CO2 Reduction

“…Raman spectra of Ni-BNC catalyst exhibit two distinct Ni-N (399.1 eV), pyrrolic-N (400.2 eV), graphitic-N (401.1 eV), and oxidized-N (404.3 eV) species, respectively (Figure 3d). [45][46][47][48][49] The B 1s XPS spectrum of Ni-BNC can be divided into four peaks around 186.8, 190.7, 191.5, and 192.2 eV, corresponding to Ni─B, B─C, B─N, and B─O bonds, respectively (Figure S13, Supporting Information). [44,50,51] To develop low-cost electrocatalysts, actived carbon (AC), a widely applied carbon material in industrial catalytic processes, was used as a carrier instead of conductive carbon black (CB) to prepare Ni-BN-AC catalysts.…”