Document Type
Article
Publication Date
4-10-2026
Department
Department of Materials Science and Engineering
Abstract
The electrochemical CO2 reduction (eCO2R) offers a compelling route for converting CO2 into value-added fuels and chemicals. Among CO2-derived products, methane (CH4) occupies a distinct position, serving both as a key intermediate for emerging cascade electro-oxidation to oxygenates and as a strategically important extraterrestrial fuel that can be generated in situ from off-planet CO2 resources. Although Cu-based catalysts capable of selectively producing CH4 have been reported, they seldom sustain high selectivity at practically relevant current densities. Here, we created a single-step co-pyrolysis strategy toward generating and anchoring Cu sub-nanometer clusters (CuSNC) atop Cu-Nx single-atom (SA) motifs embedded within N-doped carbon (NC), with controllable nanostructures through tuning of the synthesis parameters. Complementary spectroscopic analyses and density functional theory (DFT) calculations help reveal a structure−activity correlation that could guide the catalyst design. The CuSNC@NC sample synthesized at 550 °C pyrolysis temperature (best described and modeled as Cu3-CuN4 domains) represents the most effective combination of cluster size, metal-nitrogen coordination, and adsorption energetics needed to selectively promote CH4 generation versus other eCO2R products. Incorporating pulsed electrolysis and hydrophobicity-modulated transport tuning at the triple-phase boundary (TPB) further enhanced CH4 production achieving a partial CH4 current density of ∼321 mA cm−2, 53% Faradaic efficiency (FECH4), and less than 4% combined FE for other eCO2R products, simplifying downstream CH4 purification or upgrading. This work establishes generalizable principles for controlling Cu cluster atomicity and metal−nitrogen coordination, both of which are recognized determinants of CH4-efficient eCO2R.
Publication Title
ACS Catalysis
Recommended Citation
Badreldin, A.,
Minhas, M.,
Wang, S.,
Smith, G.,
Chen, S.,
Wu, S.,
Racine, C.,
Feng, J.,
Hu, Y.,
Li, T.,
&
Li, Y.
(2026).
Sub-Nanometer Nanoclusters of Copper Atop Single-Atom Copper Moieties toward Electrochemical CO2 Hydrogenation to Methane.
ACS Catalysis,
16(9), 8081-8097.
http://doi.org/10.1021/acscatal.5c09141
Retrieved from: https://digitalcommons.mtu.edu/michigantech-p2/2643
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Version
Publisher's PDF
Publisher's Statement
© 2026 The Authors. Published by American Chemical Society. Publisher’s version of record: https://doi.org/10.1021/acscatal.5c09141