Mediating heterogenized nickel phthalocyanine into isolated Ni-N3 moiety for improving activity and stability of electrocatalytic CO2 reduction

FeN4OC Nanoplates Covalently Bonding on Graphene for Efficient CO2 Electroreduction and ZnCO2 Batteries

“…Taken together, the as-prepared FeN 4 OC/Gr catalyst presents a remarkable CO 2 RR behavior including excellent CO selectivity (98.3%), high TOF (3511 h −1 ), and good stability (48 h), which is comparable to those of reported SACs (Table S5, Supporting Information). [5,9,13,15,16,[33][34][35][36][37][38][39][40][41][42] To gain an in-depth insight into the relationship between the special FeN 4 O configuration and superior CO 2 RR performance, we further carried out DFT calculations based on the models that are established on EXAFS fitting results (Figure S26, Supporting Information). The conversion of CO 2 into CO mainly involves the following three steps: i) the initial protonation of CO spontaneously form *COOH intermediate with a free energy of −0.94 eV and −0.89 eV, respectively.…”

Facile Synthesis of Hierarchically Porous Ni–N–C for Efficient CO2 Electroreduction to CO

“…The N 1s spectra of all catalysts are presented in Figures d and S11–S13. The N 1s spectra of HP-Ni-NC-X and Ni-NC-2 (Figures d and S11 and S12) are fitted into five peaks, corresponding to pyridinic-N (398.6 eV), Ni–N (399.6 eV), pyrrolic-N (400.2 eV), graphitic-N (401.4 eV), and oxidized-N (402.8 eV). , The existence of Ni–N species indicates the coordination of Ni with N atoms.…”

Promoting CO2Dynamic Activation via Micro‐Engineering Technology for Enhancing Electrochemical CO2Reduction

“…Meanwhile, the total number of electrons for Ni in Ni-C 3 N 1 moiety is the base, and the spin-down magnetic moment concentrated on Ni is 0.18 (inset of Figure 6d). The valence charge density difference for two configurations was calculated (Figure 6e Inspired by the excellent CO 2 RR performance, we assembled I-Ni SA/NHCRs and O-Ni SA/NHCRs on a GDL to prepare the cathode electrode, and selected a Zn plate as anode to construct an aqueous Zn-CO 2 battery (ZCB, Figure S45, Supporting Information), which is an upgrade and optimization based on the previous research foundation, [9] where the optimization of ZCB was combined with the design mechanism of flow cell to create triple-phase boundary (gas-solid-liquid, Figure 7a) for increasing the accessibility of Ni active sites to CO 2 molecule and improving its performance (seen the detailed design drawings of the battery in Figure S46, Supporting Information). The working principle of ZCB was shown in Figure 7b, where 1 m KHCO 3 and 6 m KOH with 0.02 m Zn(CH 3 COO) 2 were chosen as catholyte and anolyte, respectively.…”

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highly efficient CO 2 electroreduction still suffers from the sluggish kinetics owing to its chemical inertness and the limited CO 2 solubility in electrolyte solutions, [4] which is really easy for competitor of hydrogen evolution reaction (HER), [5] thus the target product selectivity and activity for CO 2 RR was suppressed. Developing efficient electrocatalysts with high selectivity and activity for a single product of CO 2 RR was a good avenue for solving the above dilemma.As competitive candidates, atomically dispersed metal catalysts composed of transition metals (e.g., iron (Fe), [6] cobalt (Co), [7,8] nickel (Ni) [9] ) have been widely investigated and rapidly developed in various reactions including HER, [8] oxygen reduction reaction (ORR), [7] oxygen evolution reaction, [8] nitrogen reduction reaction [6] and CO 2 RR [9] on the basis of their fine structure of active site and high atomic utilization, robust metal-support interaction and the ability to redecorate the coordination structure, merging the merits of both heterogeneous and homogeneous catalysts. Among this series of electrocatalysts, isolated Ni-based catalysts with unique Ni-N 4 -C moiety display satisfactory CO faradaic efficiency (FE CO ) above 80% at a wide potential window (−0.5 to −1.0 V versus RHE, reversible hydrogen electrode), [10] whereas the scarce electron density on Ni sites in Ni-N 4 -C moiety typically exhibit the high barrier energy for *COOH formation Optimizing the coordination structure and microscopic reaction environment of isolated metal sites is promising for boosting catalytic activity for electrocatalytic CO 2 reduction reaction (CO 2 RR) but is still challenging to achieve.

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