Engineering Steam Induced Surface Oxygen Vacancy onto Ni–Fe Bimetallic Nanocomposite for CO₂ Electroreduction

Abstract

Surface oxygen vacancies (Vo) regulation is an effective strategy to improve the electrochemical CO2 reduction reaction (CO2RR) performance by lowering the activation energy barrier of CO2; however, the lack of precise control over the local atomic structures severely hinders the large‐scale application of Vo‐activated electrocatalyst for CO2RR. Herein, an efficient strategy to facilitate CO2 activation is developed by introducing Vo into transition metal nanoparticles (NPs) with a steam‐assisted chemical vapor deposition method. With the steam process, abundant surface Vo are introduced into the assembled Ni–Fe bimetallic NPs composite (H‐NiFe/NG), which adjust surface Ni/Fe atoms to low‐valent coordinatively unsaturated Ni (+1)/Fe (+2) sites, serving as electron‐rich centers to adsorb and activate inert CO2 molecules. The as‐prepared H‐NiFe/NG composite exhibits excellent catalytic performance with a maximum Faradaic efficiency of 94% at −0.80 V (vs RHE) for CO production with remarkable stability. The density function theory calculations corroborate that the Ni atoms around surface Vo significantly lower the energy barrier for COOH* intermediate formation, which gives a low overpotential for reducing CO2 to CO, exhibiting superior CO2RR performance. This general synthetic strategy provides a new insight to introduce surface Vo on transition metal for efficient CO2 reduction.

Pit-embellished low-valent metal active sites customize CO2photoreduction to methanol

“…S5, Table S1, ESI †). [39][40][41] This change also affects the electronic structure of oxygen atoms: the H-60 shows the strongest O 1s peak possibly adjacent to the W 5+ at 531.4 eV (Fig. 2j).…”

Dinuclear metal synergistic catalysis for energy conversion

“…DFT calculations confirmed that H-NiFe/NG featured the lowest energy barrier for the formation of the COOH* intermediate, thus exhibiting a superior catalytic performance for the CO 2 RR. 249 Liu et al reported the synthesis of an Fe-Cu DMC for electrochemical CO 2 RR via the thermal pyrolysis of Fe-and Cu-doped ZIF-8. The Fe-Cu dual sites were confirmed by aberration-corrected HAADF-STEM given that many distinct dual dots were observed on the substrate.…”

One‐Dimensional Co‐Carbonate Hydroxide@Ni‐MOFs Composite with Super Uniform Core–Shell Heterostructure for Ultrahigh Rate Performance Supercapacitor Electrode

“…based on their atomic orbitals further proved that more active carriers exist in the lateral orbital of Co-CH@Ni-MOFs composite, which may enhance the adsorb ability and electrochemical reactivity. [44][45][46] For the molecular dynamic (MD) simulations, fluctuating curves of energy and temperature (Figure 5) obtained after adsorbing OH − on as-prepared materials revealed that a reasonable equilibrium state was reached in the 500 ps simulation. The adsorption behaviors with adsorption energy of OH − on the Co-CH, Ni-MOFs, and Co-CH@Ni-MOFs materials (Figure 6) clearly show that the heterostructure of Co-CH@Ni-MOFs increases the adsorption property for OH − ions on the interface with adsorption energy of −1.51 kcal mol −1 , higher than −0.88 kcal mol −1 of Co-CH and −1.00 kcal mol −1 of Ni-MOFs.…”