Self-Supported Porous Carbon Nanofibers Decorated with Single Ni Atoms for Efficient CO₂ Electroreduction

Abstract

Single-atom catalysts within M-N-C structures are efficient for electrochemical CO 2 reduction. However, most of them are powdered and require a coating process to load on the electrode. Herein, we developed a facile approach to the synthesis of largescale self-supported porous carbon nanofiber electrodes directly decorated with atomically dispersed nickel active sites using facile electrospinning, where poly(methyl methacrylate) was employed to tune well the distributions of pores located in carbon nanofibers. The above self-supported carbon nanofibers were applied as a gas diffusion electrode to achieve 94.3% CO Faraday efficiency and 170 mA cm −2 current density, which can be attributed to the effects of rich mesoporous structures favorable for adsorption and mass transfer of CO 2 and single nickel catalysts effectively converting CO 2 to CO. This work provides an efficient strategy to fabricate self-supported electrodes and may accelerate the progress toward industrial applications of single-atom catalysts in the field of CO 2 electroreduction.

Customization from Single to Dual Atomic Sites for Efficient Electrocatalytic CO2 Reduction to Value‐added Chemicals

“…Wang and colleagues prepared single-atom nickel-modified porous carbon nanofibers by electrostatic spinning method, and adjusted the void structure by changing the poly(methyl methacrylate) (PMMA) addition (NiÀ PCNF-xPMMA, x is the PMMA addition amount) (Figure 7a). [77] Compared with NiÀ PCNF-0.4PMMA and NiÀ PCNF-0.6PMMA, NiÀ PCNF0.5PMMA prepared with PMMA addition amount of 0.5 g possessed a more abundant mesoporous structure (2 ~50 nm) and its specific surface area was far (688.3126 m 2 g À 1 ) larger than the latter two, which not only facilitate the mass transfer of CO 2 (Figure 7b-c). Moreover, these high surface areas and abundant mesoporous structures [77] Copyright 2022, American Chemical Society.…”

“…[77] Compared with NiÀ PCNF-0.4PMMA and NiÀ PCNF-0.6PMMA, NiÀ PCNF0.5PMMA prepared with PMMA addition amount of 0.5 g possessed a more abundant mesoporous structure (2 ~50 nm) and its specific surface area was far (688.3126 m 2 g À 1 ) larger than the latter two, which not only facilitate the mass transfer of CO 2 (Figure 7b-c). Moreover, these high surface areas and abundant mesoporous structures [77] Copyright 2022, American Chemical Society. allowed more Ni active sites to be exposed to the electrolyte of CO 2 RR.…”

“…(e) Catalytic stability test at −1.3 V vs. RHE for 24 h in the H‐cell. Reproduced with permission [77] . Copyright 2022, American Chemical Society.…”

Ceria -Mediated Dynamic Sn0/Snδ+ Redox Cycle for CO2 Electroreduction

“…Guided by the above-mentioned theoretical calculation results, the CeO 2 –SnO 2 nanofibers with different Ce contents (0, 5, 16, 33, and 50%) were prepared by a facile electrospinning method (Figure a). , Poly­(vinyl pyrrolidone) (PVP) was used as a scaffold to add into the mixture of both Sn and Ce precursors. After an annealing process in the air, Sn and Ce ions were oxidized into the corresponding oxides, while PVP was removed completely.…”

Stabilizing Cu Catalysts for Electrochemical CO2 Reduction Using a Carbon Overlayer

“…It is a promising carbon-neutral technology to produce useful chemicals via CO 2 electroreduction reaction (CO 2 RR) using renewable electricities. Multicarbon products (C 2+ ) are preferred for their high market values and energy densities. − Copper is the only monometallic catalyst able to produce C 2+ products due to its moderate adsorption energy of key reaction intermediate *CO on surfaces for further deep reduction and C–C bond formation. − …”