Rational Design of Fe-Ni-Based Bimetallic Electrocatalyst with in situ Grown Carbon Nanotubes for Efficient CO 2 Electrochemical Reduction

Unofficial AI-generated summary based on the public title and abstract. Not an official translation.

🔬研究者:Offers a clear methodology for designing MOF-derived bimetallic catalysts with in situ CNT growth for high-performance CO2RR.

🏢実務担当者:Could inform the development of cost-effective catalysts for industrial CO2 electrolysis, potentially reducing reliance on precious metals.

🏛政策担当者:Supports the technological feasibility of electrochemical CO2 utilization, which can inform policy on carbon recycling and CCUS incentives.

Excessive emissions of carbon dioxide (CO 2 ) resulting from anthropogenic activities, such as fossil fuel combustion and industrial processes, significantly contribute to global climate change. Strategies to mitigate CO 2 emissions are generally classified into two primary approaches: (i) physical capture and storage, and (ii) the conversion of CO 2 into value-added chemicals. The electrochemical reduction of carbon dioxide (CO₂RR) has emerged as a promising pathway for facilitating sustainable energy transitions. The primary product of CO 2 RR, carbon monoxide (CO), serves as a versatile and essential industrial feedstock for synthesizing various value-added chemicals, such as methanol and olefins. Although noble metals, such as Au and Ag, are extensively employed as catalysts to produce CO as the primary product, their limited availability and high cost restrict their widespread application. Consequently, there is a significant demand for the development of catalysts composed of earth-abundant elements that exhibit high activities, selectivity, and stability. In contrast, metals such as Ni and Fe typically favor the hydrogen evolution reaction over CO 2 RR. However, when these metals are anchored onto nitrogen-carbon substrates, their catalytic activity towards the CO 2 RR can be significantly enhanced. Metal-organic frameworks (MOFs) are characterized by their porous architectures, which are constructed through strong coordination between metal ions and organic ligands. MOFs offer a highly versatile platform for catalyst design owing to their well-defined crystalline structures, high surface areas, and tunable pore environments. The modular nature of MOFs enables precise control over the spatial distribution of active sites and facilitates post-synthetic modification, thereby allowing rational optimization of catalytic activity, selectivity, and stability. Consequently, MOF-based catalysts provide unique opportunities for the development of efficient and tailor-made catalytic systems that are difficult to achieve using conventional porous materials. In this study, carbon nanotubes (CNTs) were grown in situ to synthesize an Fe/Ni–N–CNT catalyst, which was employed for the CO 2 RR as an alternative to precious metal catalysts. To synthesize an Fe/Ni-N-CNT catalyst, we utilized a zeolitic imidazolate framework (ZIF), a variant of MOFs, as the precursor substrate. By substituting Zn sites with Fe and Ni in a ZIF-8-based precursor, dual metal centers were formed within a nitrogen-carbon matrix. Simultaneously, highly conductive in situ grown CNTs significantly enhance the electrical conductivity of the catalyst and improves its electrochemical activity. Additionally, the one-dimensional CNT network facilitates CO desorption, improves mass transfer, and stabilizes the electrode/electrolyte interface. Electrochemical measurements were conducted under potentiostatic conditions over a wide potential range using a membrane electrode assembly (MEA) cell. The CO₂RR proceeds concurrently with the anodic oxygen evolution reaction. Under these conditions, Fe/Ni-N-CNT maintained a CO Faradaic efficiency above 95% over a wide potential range and reached a current density of 150 mA cm⁻² at -2.2 V (cell voltage). Overall, this work demonstrates that the rational design of MOF-derived Fe/Ni-N-CNT catalysts enables the efficient and selective electrochemical CO 2 RR to CO under relevant conditions. The synergistic interaction between the dual Fe-Ni active sites and the conductive CNT network enhances catalytic activity, selectivity, and stability while facilitating mass transport and charge transfer in a MEA configuration. These findings confirm the success of the MOF-derived catalyst design strategy for promoting efficient and selective CO 2 electroreduction.

• semanticscholar https://doi.org/10.1149/ma2026-01412095mtgabsfirst seen 2026-07-20 05:28:47