Efficient electrocatalytic conversion of carbon monoxide to propanol using fragmented copper

Interplay between halides in the electrolyte and the chemical states of Cu in Cu-based electrodes determines the selectivity of the C2product

The interaction between selectivity/activity (CH₄and C₂H₄) and electrode structure (Cu⁰, Cu⁺and Cu²⁺)/electrolyte properties (Cl⁻, Br⁻and I⁻) was investigated.

Frustrated Lewis pairs photocatalyst for visible light-driven reduction of CO to multi-carbon chemicals

Photocatalytic reduction of carbon monoxide (CO), an increasingly available and low-cost feedstock that could benefit from CO₂ reduction, to high value-added multi-carbon chemicals, is significant for desirable carbon cycling, as well as high efficiency conversion and high density storage of solar energy. However, developing low cost but highly active photocatalysts with long-term stability for CO coupling and reduction remains a great challenge. Herein, by density functional theory (DFT) computations and taking advantage of the frustrated Lewis pairs (FLPs) concept, we identified a complex consisting of single boron (B) atom decorated on the optically active C₂N monolayer (i.e., B/C₂N) as an efficient and stable photocatalyst for CO reduction. On the designed B/C₂N catalyst, CO can be efficiently reduced to ethylene (C₂H₄) and propylene (C₃H₆) both with a free energy increase of 0.22 eV for the potential-determining step, which greatly benefits from the pull-push function of the B-N FLPs composed of the decorating B atom and host N atoms. Moreover, the newly designed B/C₂N catalyst shows significant visible light absorption with a suitable band position for CO reduction to C₂H₄ and C₃H₆. All these unique features make the B/C₂N photocatalyst an ideal candidate for visible light driven CO reduction to high value-added multi-carbon fuels and chemicals.

Cascade Reactions in Nanozymes: Spatially Separated Active Sites inside Ag-Core-Porous-Cu-Shell Nanoparticles for Multistep Carbon Dioxide Reduction to Higher Organic Molecules

Enzymes can perform complex multistep cascade reactions by linking multiple distinct catalytic sites via substrate channeling. We mimic this feature in a generalized approach with an electrocatalytic nanoparticle for the carbon dioxide reduction reaction comprising a Ag core surrounded by a porous Cu shell, providing different active sites in nanoconfined volumes. The architecture of the nanozyme provides the basis for a cascade reaction, which promotes C-C coupling reactions. The first step occurs on the Ag core, and the subsequent steps on the porous copper shell, where a sufficiently high CO concentration due to the nanoconfinement facilitates C-C bond formation. The architecture yields the formation of n-propanol and propionaldehyde at potentials as low as -0.6 V vs RHE.

Dual-Facet Mechanism in Copper Nanocubes for Electrochemical CO2 Reduction into Ethylene

The product selectivity in the electrochemical reduction of carbon dioxide depends on the structure of the copper electrode. Cube-shaped copper catalysts, enclosed by {100} terraces, {110} edges, and {111} corners, exhibit a size-dependent enhanced only selectivity toward C₂ products and ethylene in particular. However, the underlying chemical reasons for such a behavior are not fully understood. This computational work toward ethylene formation investigates the carbon dioxide electroreduction mechanism over copper nanocubes. The analysis of the different pathways illustrates that the thermodynamic picture is limited in describing the formation of this product. Based on the activation barriers associated with the limiting C₂ formation step, we identify a dual-facet mechanism occurring at the interface between the {100} terraces and {110} edges. These results highlight that the reactivity of shape-controlled nanocatalysts goes beyond the facet-selectivity observed in single crystals owing to the possible synergies arising at the intersection between the enclosing crystalline planes.

Understanding the Roadmap for Electrochemical Reduction of CO2 to Multi-Carbon Oxygenates and Hydrocarbons on Copper-Based Catalysts

Electrochemical reduction of CO₂ to high-energy-density oxygenates and hydrocarbons beyond CO is important for long-term and large-scale renewable energy storage. However, the key step of the C-C bond formation needed for the generation of C₂ products induces an additional barrier on the reaction. This inevitably creates larger overpotentials and greater variety of products as compared to the conversion of CO₂ to C₁ products. Therefore, an in-depth understanding of the catalytic mechanism is required for advancing the design of efficient electrocatalysts to control the reaction pathway to the desired products. Herein, we present a critical appraisal of reduction of CO₂ to C₂ products focusing on the connection between the fundamentals of reaction and efficient electrocatalysts. An in-depth discussion of the mechanistic aspects of various C₂ reaction pathways on copper-based catalysts is presented together with consideration of practical factors under electrocatalytic operating conditions. By providing some typical examples illustrating the benefit of merging theoretical calculations, surface characterization, and electrochemical measurements, we try to address the key issues of the ongoing debate toward better understanding electrochemical reduction of CO₂ at the atomic level and envisioning the roadmap for C₂ products generation.

Nitrogen-doped metal-free carbon catalysts for (electro)chemical CO2 conversion and valorisation

This review focuses on the recent developments made in the fabrication of N-doped carbon materials for enhanced CO₂ conversion and electrochemical reduction into high-value-added products.