Steering Carbon Hybridization State in Carbon-Based Metal-free Catalysts for Selective and Durable CO₂ Electroreduction

Abstract

Electrocatalytic CO2 reduction using metal-free catalysts offers a promising and cost-effective approach to global carbon neutrality. However, metal-free catalysts frequently suffer from unsatisfactory catalytic performances, especially a low current density and poor stability. Herein, by modulating the orbital hybridization state of carbon, we strategically design a regulable sp3 and sp2 hybrid carbon interface embedded with adjacent boron and nitrogen sites in carbon-based metal-free catalysts for CO2 electroreduction. Soft X-ray chemical imaging visually uncovers that the electronic structure and bonding configuration of the boron active site at the hybrid carbon interface are modulated by the neighboring nitrogen site and sp3 carbon. The concomitant electron density reconfiguration around the interface not only delivers optimum upshift of the boron p-band center, and accordingly the moderate valence-electron depletion, to stabilize the *OCHO intermediate favorable for HCOOH generation but also weakens the boron–carbon and boron–hydrogen hybridization of competing *COOH and *H species, respectively, to promote HCOOH selectivity over CO and H2. The designed electrocatalyst realizes a record-high formate partial current density of up to 50.8 mA cm–2 among metal-free catalysts in the H-cell and maintains a high Faradaic efficiency (>90%) over 108 h. This work elevates the carbon interface design with a tailored carbon hybridization state for efficient CO2 electroreduction.

Dynamic Restructuring of Cu7S4/Cu for Efficient CO2 Electro‐reduction to Formate

“…Thirdly, $${{CO}_{2}^{^{\ast}-}}$$ was protonated from HCO 3 − and adsorbed $${{HCOO}^{^{\ast}-}}$$ was formed by obtaining second $${{e}^{-}}$$ from the electrode. Then, formate was produced [5b,20] . To further unveil the kinetic information for the formate generation, Tafel analysis was administered in Figure 3b.…”

C60 and Derivatives Boost Electrocatalysis and Photocatalysis: Electron Buffers to Heterojunctions

“…Carbon-based, metalfree catalysts are however potential practical substitutes for noble metal-based catalysts because of good catalytic activity, selectivity and stability. [225][226][227][228][229][230] It is concluded that C 60 and derivatives are significant to development of increasingly efficient and advanced electrocatalysts and photocatalysts. This is because of electron acceptor properties, distinctive heterostructure(s) and physicochemical characteristics and electron buffers, together with high structural integrity.…”

Selective and Scalable CO2 Electrolysis Enabled by Conductive Zinc Ion-Implanted Zeolite-Supported Cadmium Oxide Nanoclusters

“…In general, the CO molecule exhibits a strong affinity to coordinate with transition metals. , If the interaction between CO and the active metal site is too strong, the CO desorption process will become difficult, thereby constraining the catalytic rate of the CO 2 RR, i.e., the poisoning effect. − Attention was usually paid to enhancing the stabilization of *COOH, the key intermediate of the CO pathway, for high performance; however, this correspondingly raises the adsorption energy of the *CO intermediate, leading to a higher energy barrier of *CO desorption. Thus, how to stabilize *COOH while moderately decreasing the affinity of *CO is key and challenging to improve the electrocatalytic performance of the CO 2 RR to CO. To this end, incorporating a suitable support and tuning the electronic and geometric interactions between metal atoms and the support are an effective approach to regulate the adsorption strength and binding configuration of intermediates on the catalyst surfaces. − Besides, metal atoms that have strong binding to supports could resist aggregation but may become less reactive, while weaker binding typically signifies a greater susceptibility to loss of active sites when subjected to harsh cathodic potentials. , Therefore, appropriate selection of supports and a rational understanding of the metal–support interaction are the keys to designing electrocatalysts with high catalytic performance at industrially relevant current densities for satisfying the practical application of the electrochemical CO 2 RR.…”