Fe-Co Catalysts Research Articles

Evaluation of the effect of various catalysts on the yield of hydrogen and nanofiber carbon during pyrolysis of hydrocarbon gases

This article provides a literary review of pyrolysis catalysts for the production of alternative energy fuel in the form of hydrogen, as well as an equally useful product of nanofiber carbon. A theoretical analysis of the effectiveness of the use of catalysts based on the yield of a useful product was carried out. It was found that the most promising catalysts for industrial use are high-percentage nickel and copper-nickel catalysts. Most effective catalyst in the process of obtaining hydrogen by the method of catalytic decomposition of hydrocarbon gases is the 40Ni/SiO2 catalyst, the yield of hydrogen when used is 80.7 mol/gcat, and the highest yield of nanofiber carbon 449 g/gcat makes it possible to obtain a bimetallic catalyst (75Ni-15Cu)/Al2O3. The methods of preparation of applied catalysts are also considered, the advantages and disadvantages of each are described. Keywords: bimetallic Fe-Co catalysts; bimetallic Ni-Cu catalysts; pyrolysis catalysts; conversion of hydrocarbon gases; nanofiber carbon; nickel catalyst; hydrogen production.

Transformation of CoFe2O4 spinel structure into active and robust CoFe alloy/N-doped carbon electrocatalyst for oxygen evolution reaction

Electrochemical water splitting is an environmentally benign technology employed for H2 production; however, it is critically hampered by the sluggish kinetics of the oxygen evolution reaction (OER) at the positive electrode. In this work, nitrogen-doped carbon-coated CoFe electrocatalysts were synthesized via a three-step route comprising (1) hydrothermal reaction, (2) in-situ polymerization of dopamine and (3) carbonization. The effect of carbonized polydopamine on the overall physicochemical properties and electrochemical activity of CoFe catalysts was systematically studied. By controlling and optimizing the ratio of CoFe2O4 and dopamine contents, a transformation of the CoFe2O4 structure to CoFe alloy was observed. It was found that CoFe/NC30% (prepared with 30% dopamine) exhibits an excellent catalytic activity towards OER. A small overpotential of 340 mV was required to generate a current density of 10 mA cm−2 in a 1.0 M KOH electrolyte. More importantly, the CoFe/NC30% catalyst reflected exceptional durability for at least 24 h. This research sheds light on the development of affordable, highly efficient, and durable electrocatalysts for OER.

Bimetallic FeCo−N−C Catalyst for Efficient Oxygen Reduction Reaction

AbstractOxygen reduction reaction (ORR) is being deeply studied because of its significance in energy storage and conversion. It is an urgent and challenging task to explore low‐cost ORR catalysts with excellent activity and outstanding long‐term stability. Herein, we report an efficient bimetallic FeCo catalyst based on nitrogen‐doped carbon (FeCo−NC) for ORR by pyrolysis of FeCo‐1,10‐phenanthroline complexes (FeCo‐phen) supported on ZIF‐8. The as‐synthesized FeCo−NC catalyst shows excellent ORR activity, improved durability and excellent methanol cross poisoning resistance, which are ascribed to the formation of metal‐N−C active sites, the synergistic effect between Fe and Co, as well as the porous structure.

Synergistic degradation of Methylene Blue by novel Fe-Co bimetallic catalyst supported on waste silica in photo-Fenton-like system

In this present study, a novel method to fabricate bimetallic Fe-Co catalyst supported on waste silica was investigated for the photo-Fenton-like (PFL) degradation of Methylene Blue (MB) dye. The uniqueness of this work is on the preparation of the catalyst via fluidized-bed crystallization (FBC) process. Under the optimum conditions of initial pH of 3.0, 3.0 mM of H2O2, and 1.0 g L-1 of FBC-derived Fe-Co/SiO2 catalyst (fFCS), the maximum response for the decoloration and mineralization efficiencies of 20 mg L-1 of MB in 60 min were 100 and 65%, respectively. Compared to the impregnated Fe-Co/SiO2 catalyst, the fFCS catalyst exhibited comparable decoloration and mineralization efficiencies, and relatively lower metal leaching for both iron and cobalt. Superoxide radical was unveiled to be the dominant reactive oxygen species in the PFL system over the fFCS catalyst. The catalysts were characterized by Fourier Transform Infrared spectroscopy, Energy Dispersive X-ray spectroscopy and Scanning Electron Microscopy. The results show the successful incorporation of iron and cobalt on the surface of the SiO2 support material.

MOF-Derived Porous Carbon-Supported Bimetallic Fischer–Tropsch Synthesis Catalysts

Generally, incorporating different metals in a catalyst can provide a synergistic effect for enhancing the catalytic performance. However, the interaction between the two metals and the effect on the catalytic performance seem elusive. In this work, a bimetallic metal–organic framework (MOF) is synthesized, and then, a novel bimetallic catalyst is prepared for Fischer–Tropsch synthesis (FTS). The combination of these different metals and a MOF-derived porous carbon supporter offers a unique active surface structure that may lead to improved catalytic performance. Herein, alloy-type structures were observed in FeCo and FeNi bimetallic MOF-derived catalysts, while a solid solution with a spinel structure were observed in FeMn and FeZn bimetallic MOF-derived catalysts. The bimetallic catalysts supported on MOF-derived porous carbon display stable and excellent catalytic performance during 100 h compared with a single-metal Fe catalyst. X-ray diffraction measurement, X-ray photoelectron spectroscopy, and H2 temperature-programed reduction were employed to study the synergistic effect of bimetallic components on surface composition and electronic and reduction properties accordingly. The relationship between catalytic performance and catalyst composition was deeply studied. These research work results will provide a new approach to design novel bimetallic FT catalysts.

Magnetic Co/Fe nanocomposites derived from ferric sludge as an efficient peroxymonosulfate catalyst for ciprofloxacin degradation

• Cobalt adsorbed on ferric sludge was recycled to create bimetallic catalyst via a facile solvothermal method. • Co/Fe nanocomposites derived from ferric sludge (CoFe@FS) exhibited an excellent performance toward PMS. • SO 4 •− , • OH, O 2 •− and 1 O 2 were produced from PMS activation by synergetic effect of Co and Fe on the catalyst surface. • The possible degradation mechanism of CIP is proposed based on DFT calculations and LC/MS analyses. • This is a cost-effective method to achieve “treating wastewater by waste residuals”. Ferric sludge, generated during drinking water purification process, can be considered as a promising support with potential iron resource. Herein, magnetic bimetallic Co/Fe nanocomposite derived from ferric sludge (CoFe@FS) was created via a facile solvothermal treatment and employed as an efficient peroxymonosulfate (PMS) activator for the elimination of antibiotic ciprofloxacin (CIP) in water. CoFe@FS exhibited nano-sphere structure with the composites of CoO, CoFe 2 O 4 and SiO 2 crystals and presented excellent catalytic performance with 97.3% removal efficiency of 10 mg/L CIP within 15 min. Sulfate radicals (SO 4 •− ), hydroxyl radicals ( • OH) superoxide radicals (O 2 •− ) and singlet oxygen ( 1 O 2 ) all contributed to CIP degradation, and SO 4 •− functioned as the dominant reactive species in this activation system. CoFe@FS composite exhibited great reusability due to the strong Co/Fe-Si interaction and was able to regenerate by a simple solvothermal process. The CIP degradation mechanism in the CoFe@FS/PMS system were also proposed based on density functional theory (DFT) calculations and analysis of intermediate products. Overall, the magnetic Co/Fe bimetallic catalyst derived from ferric sludge could be employed as high-efficiency and low-cost candidate for the degradation of refractory organic contaminants. This work not only provides a promising reclamation strategy of water treatment waste from ferric sludge to high-effective catalyst, but also clarifies the mechanisms of PMS activation and CIP degradation. The more stable bimetallic CoFe catalysts derived from waste sludge need to be developed in the future study to relieve the occurrence of metal leaching.

Atomically Dispersed Fe-Co Bimetallic Catalysts for the Promoted Electroreduction of Carbon Dioxide

HighlightsX-ray photoelectron spectroscopy results confirmed the increased number of M–N sites in the bimetallic Fe–Co catalyst.Synchrotron-based X-ray absorption fine structure demonstrated that the interaction in the coordination environments of the different transition metal sites facilitated the CO production in electroreduction reaction of CO2 (ECO2RR).This bimetallic strategy has also been extended to fabricate other catalysts such as Cu–Co and Ni–Co, which also exhibited enhanced performance for ECO2RR.

Highly Dispersed CoFe Catalyst for Selective Hydrogenation of Biomass‐Derived Furfural to Furfuryl Alcohol

Biorefinery to fabricate biofuels, chemicals, and materials has attracted much attention. Herein, a highly dispersed non‐noble CoFe immobilized on nitrogen‐doped carbon catalyst is prepared via a template sacrificial method. Owing to the synergetic effect of Co and Fe, the high dispersity of CoFe nanoparticles and large specific surface area, the optimized Co9‐Fe1‐NC catalyst exhibits high activity for the selective hydrogenation of furfural (FAL) to furfuryl alcohol (FOL). Hundred percentage conversion of FAL and 99% selectivity of FOL are obtained at 120 °C with 1 MPa H2 for 4 h, which is superior to most of the reported nonprecious catalysts. Moreover, the Co9‐Fe1‐NC catalyst can also catalyze the hydrogenation of nitro and carbonyl compounds efficiently. The mechanism of hydrogenation of FAL is revealed by density functional theory calculations. This work provides a promising synthetic strategy for the rational structural design of efficient selective hydrogenation catalysts.

Facile synthesis of carbon quantum dot ‑carbon nanotube composites on an eggshell-derived catalyst by one-step chemical vapor deposition

Carbon nanotubes (CNTs) based composites such as carbon quantum dot-CNT (CQD-CNT) demonstrate excellent performance in the fields of bioimaging and biomedicine. Nevertheless, CQD-CNT composites were mostly prepared by multiple and cumbersome steps, including the synthesis of CQDs, functionalization of CNTs and subsequent assembly of CQDs on CNTs. Here, a facile one-step synthesis of CQD-CNT was successfully conducted on an active CaO supported FeCo (Fe-Co/CaO) catalyst derived from waste eggshells via chemical vapor deposition, and other CNT-based composites such as carbon fiber-graphene sheet-CNT (CNF-GNS-CNT) and CNF-CNT as well as CNTs were also synthesized by modulating the catalyst support, growth temperature and growth time. The catalysts and produced CNTs and CNT-based composites were analyzed by multiple characterization tools. The results showed that nano CaO supported FeCo catalyst only synthesized MWCNTs, whereas Fe-Co/CaO was favorable for the synthesis of CNT-based composites. Cobalt oxides and iron oxides were well dispersed in the fresh Fe-Co/CaO catalyst, and FeCo alloy particles of different sizes were formed after catalyst reduction and heating to different growth temperatures. At a low growth temperature of 750 °C, CNF-GNS-CNT was synthesized on Fe-Co/CaO, in which CNTs and CNFs were grown on small (~10 nm) and larger (~30 nm) metal particles, respectively, whereas GNSs were mainly produced on CaO. At a high growth temperature of 850 °C, surface area and pore volume of catalysts decreased greatly, and higher solubility of carbon atoms in metal particles resulted in less desorbed CHx, which is not favorable for the growth of GNSs. Instead, CQD-CNT composites were selectively synthesized at 850 °C, which was ascribed to the oxidation corrosion of CNFs by OH radicals, but with the extension of growth time, only CNTs were produced due to the complete oxidation of CQDs. Further, larger metal particles were produced at a higher temperature of 950 °C, which were wrapped by graphite, and the partial deactivation of metal particles led to a few small particles remained active for CNT growth with a low carbon yield.

Rationally Designed, Efficient, and Earth-Abundant Ni–Fe Cocatalysts for Solar Hydrogen Generation

Rationally Designed, Efficient, and Earth-Abundant Ni–Fe Cocatalysts for Solar Hydrogen Generation

Co-Fe Nanoparticles Wrapped on N-Doped Graphitic Carbons as Highly Selective CO2 Methanation Catalysts.

Pyrolysis of chitosan containing various loadings of Co and Fe renders Co–Fe alloy nanoparticles supported on N-doped graphitic carbon. Transmission electron microscopy (TEM) images show that the surface of Co–Fe NPs is partially covered by three or four graphene layers. These Co–Fe@(N)C samples catalyze the Sabatier CO2 hydrogenation, increasing the activity and CH4 selectivity with the reaction temperature in the range of 300–500 °C. Under optimal conditions, a CH4 selectivity of 91% at an 87% CO2 conversion was reached at 500 °C and a space velocity of 75 h–1 under 10 bar. The Co–Fe alloy nanoparticles supported on N-doped graphitic carbon are remarkably stable and behave differently as an analogous Co–Fe catalyst supported on TiO2.

A novel Fe-Co double-atom catalyst with high low-temperature activity and strong water-resistant for O3 decomposition: A theoretical exploration

Developing catalysts with high activity, durability, and water resistance for ozone decomposition is crucial to regulate the pollution of ozone in the troposphere, especially in indoor air. To overcome the shortcomings of metal oxide catalysts with respect to their durability and water resistance, Fe-Co double-atom catalyst (DAC) is proposed as a novel catalyst for ozone decomposition. Here, through a systematic study using density functional theory (DFT) calculations and microkinetic modeling, the adsorption and catalytic decomposition of O3 on Fe-Co DAC have been examined based on adsorption configuration, orbital hybridization, and electron transfer. Based on Eley-Rideal (E-R) and Langmuir-Hinshelwood (L-H) reaction mechanisms, the mechanisms of ozone decomposition on Fe-Co DAC were explored by analyzing reaction paths and energy variations. To confirm the water-resistant of Fe-Co DAC, competitive adsorption behavior between O3 and dominant environmental gases was discussed through ab initio molecular dynamic (AIMD) simulation. The dominant reaction mechanism of ozone decomposition is L-H and the rate-determining step is the desorption of the first oxygen molecule from the surface of Fe-Co DAC which has an energy barrier of 0.78 eV. Due to this relatively low energy barrier and high turnover frequency (TOF), the optimal operation window of catalytic O3 decomposition on Fe-Co DAC is <500 K suggesting that catalytic decomposition of O3 on Fe-Co DAC can occur at room temperature. This theoretical study provides new insights for designing novel catalysts for ozone decomposition and fundamental guidance for subsequent experimental research.

Hetero-structural mass transfer channel boosts electrocatalytic oxygen reactions of metallic catalyst

Large-scale application of zinc air batteries (ZABs) is impeded by the lack of efficient and cost-effective bifunctional oxygen catalysts. In this work, hetero-porous is rationally engineered for the carbon encapsulated CoFe catalyst, which is highly active toward both oxygen evolution reaction (OER) and oxygen evolution reaction (ORR). The hs-CoFe catalyst with “plate reactor” structure is facilely synthesized by combining the selective etching and reduced graphene oxide supporting to construct pores with size of 10–100 nm and 100–1000 nm, respectively, for smooth mass transfer. OER/ORR activities are significantly boosted, and difference between the potential to deliver 10 mA/cm2 OER and half wave potential of ORR is therefore lowered to 0.608 V while this potential difference of Pt/C-IrO2 is 0.732 V. The corresponding ZAB exhibits a maximum power density of 232 mW/cm2, which sheds light on providing a novel strategy for oxygen reaction catalyst designation.

Influence of Ni on Fe and Co-Fe Based Catalysts for High-Calorific Synthetic Natural Gas

Fe-Ni and Co-Fe-Ni catalysts were prepared by the wet impregnation method for the production of high-calorific synthetic natural gas. The influence of Ni addition to Fe and Co-Fe catalyst structure and catalytic performance was investigated. The results show that the increasing of Ni amount in Fe-Ni and Co-Fe-Ni catalysts increased the formation of Ni-Fe alloy. In addition, the addition of nickel to the Fe and Co-Fe catalysts could promote the dispersion of metal and decrease the reduction temperature. Consequently, the Fe-Ni and Co-Fe-Ni catalysts exhibited higher CO conversion compared to Fe and Co-Fe catalysts. A higher Ni amount in the catalysts could increase C1–C4 hydrocarbon production and reduce the byproducts (C5+ and CO2). Among the catalysts, the 5Co-15Fe-5Ni/γ-Al2O3 catalyst affords a high light hydrocarbon yield (51.7% CH4 and 21.8% C2–C4) with a low byproduct yield (14.1% C5+ and 12.1% CO2).

CO2 methanation catalyzed by a Fe-Co/Al2O3 catalyst

Carbon dioxide (CO2) hydrogenation to methanation is a potential way for alleviating greenhouse effect and storing energy sources. Here, alumina supported Fe-Co catalysts were synthesized and used for the CO2 methanation. Comparing with supported Fe/Al2O3 or Co/Al2O3 catalysts, the Fe-Co/Al2O3 catalysts showed superior catalytic performance under mild reaction conditions (280 °C and 0.2 MPa), whose reaction rate was 8.7 μmol gcat−1 s−1. It was 3 times higher than that of 2.4 μmol gcat−1 s−1 for the Fe/Al2O3 catalysts and 2.8 μmol gcat−1 s−1 for the Co/Al2O3 catalysts. Based on the comprehensive investigations by the temperature-programmed reduction by hydrogenation (H2-TPR), in situ X-ray diffraction (XRD) and catalytic test in different integration manner of catalysts, the cooperative effect between Fe and Co was determined in the Fe-Co/Al2O3 catalyst. The presence of Fe species effectively reduced the working pressure of the reaction and the Co species directly acted on the CO2 conversion and CH4 formation. When compared to Fe/Al2O3 or Co/Al2O3 catalysts, the reducibility of metals and adsorption capacity for CO2 and H2 promoted a lot in the Fe-Co/Al2O3 catalyst, leading to the enhanced reactivity for CO2 methanation.

Efficient Transfer Hydrogenolysis of 5-Hydromethylfurfural to 2,5-Dimethylfuran over CoFe Bimetallic Catalysts Using Formic Acid as a Sustainable Hydrogen Donor

Currently, developing high-performance non-noble metal catalysts for the conversion of biomass-derived compounds to valuable chemicals or biofuels remains a great challenge. Herein, surface CoFeOₓ-decorated bimetallic CoFe catalysts were developed via a Co–Mg–Fe layered double hydroxide precursor strategy and utilized for the transfer hydrogenolysis of 5-hydromethylfurfural (HMF) into 2,5-dimethylfuran (DMF) with the help of formic acid as the sustainable hydrogen donor. The as-fabricated CoFe bimetallic catalyst exhibited excellent catalytic performance with a high yield of DMF (>92%). Contrarily, monometallic Co-based catalyst delivered a much lower DMF yield. The structural characterizations and catalytic experiments demonstrated that the catalytic behavior of bimetallic CoFe catalysts was correlated with the appropriate combination of highly dispersed bimetallic metallic nanoparticles and abundant oxygen vacancies originating from surface CoFeOₓ species, as well as favorable surface basic sites, thereby facilitating the dehydrogenation of formic acid and improving the affinity for carbonyl reduction, which promoted the selective hydrogenation/hydrogenolysis of carbonyl or hydroxymethyl group in HMF and reaction intermediates. Furthermore, excellent structural advantages of as-fabricated CoFe catalyst, such as high alloying degree of CoFe and strong metal–support interactions, endowed it with good stability and regeneration performance. The present bimetal-defect interfacial engineering strategy may provide a potential guide for the rational design of high-performance non-noble-metal catalysts for a variety of heterogeneous catalysis processes in terms of the conversion of biomass source.

Effect of EDTA-2Na modification on Fe-Co/Al2O3 for hydrogenation of carbon dioxide to lower olefins and gasoline

Capturing and utilization of carbon dioxide (CO2) not only leads to effective use of carbon resources, but also alleviates environmental pollution caused by increasing concentration of CO2, thus making it a hot research topic in recent years. In this study, a series of highly dispersed iron-cobalt (Fe-Co) catalysts was prepared by ethylenediaminetetraacetic acid disodium salt (EDTA-2Na) modification, which could efficiently convert CO2 into high value-added chemicals (C2-C4= and C5-C11). X-ray diffraction (XRD) analysis showed that the addition of a small amount of Co and EDTA-2Na contributed to enhance the sintering resistance of Fe species. During the calcination process, EDTA4− can be decomposed into small organic molecules with reducibility, thus promoting the reduction of iron species. The CO temperature-programmed desorption (CO-TPD) results showed that cobalt enhanced the adsorption and activation of intermediate CO on NaxFe-Co catalyst, thereby promoting the catalytic conversion of CO2. The complexation of EDTA promotes the synergistic effect of Fe-Co bimetals, enhances the chemical adsorption of CO2. Sodium in EDTA-2Na promotes the surface basicity of the catalysts, which is favored for improving the product distribution of hydrocarbons. At lower H2/CO2 (1/1) ratio, the EDTA-2Na modified Fe-Co/Al2O3 catalyst exhibited high conversion of CO2 (32.8 %) and excellent selectivity toward high value-added chemicals. The selectivity of by-product CO was only 8.1 %; and C2-C4= (32.5 %) and C5-C11 (46.3 %) accounted for ∼79 % selectivity among the hydrocarbons generated.

One-pot hard template synthesis of mesoporous spinel nanoparticles as efficient catalysts for low temperature CO oxidation.

Co-Fe, Cu-Cr, and Co-Mnmixed oxide catalysts were prepared using a one-pot hard template synthesis method, and their catalytic performance was investigated before and after the rearrangement of the template. To evaluate the structural properties of the catalysts, various analyses were employed, including the BET, XRD, H2-TPR, FE-SEM, EDX, and X-ray digital mapping of the elements. The results indicated that the rearrangement of the catalyst structure had a profound effect on the structural and catalytic properties, so that in all three synthesized catalysts, the specific surface and the reducibility increased significantly, and the crystalline structure and morphology of the catalysts changed remarkably. The specific surface area of the CoFe, CuCr, and CoMn catalysts increased from 3.5, 1.1, and 72.9m2/g to 151.3, 52.8, and 108.0m2/g, respectively. These structural changes significantly increased the catalytic performance. The results indicated that the 100% conversion temperature of the CoMn catalyst as the optimal sample after rearrangement was reduced from 250 to 125°C. Also, the stability of the CoMn catalyst in dry and wet conditions was investigated and the results indicated that the presence of water vapor reduced the activity and stability of the catalyst. The activation energy was also calculated on Co-Mn catalyst (59.5kJ/mol) and the results confirmed that the most probable mechanism for this reaction was the MVK mechanism.

A highly efficient Fenton-like catalyst based on isolated diatomic Fe-Co anchored on N-doped porous carbon

The Fenton-like process provides a promising pathway to produce enormous reactive radicals for the elimination of refractory organic pollutants in environmental remediation. In the design of heterogeneous Fenton-like catalyst, significant progress has been made for nano- and micro-structures, but catalysts with atomic-scaleactive sites, particularly dual-metal single-atom, has been rarely observed. Herein, we report a highly efficient Fenton-like catalyst based on isolated diatomic Fe-Co anchored on N-doped porous carbon. This diatomic Fe-Co catalyst is robust and highly active in the heterogeneous activation of peroxymonosulfate (PMS) for BPA degradation, showing an outstanding turnover frequency exceeding 60.62 min−1. A variety of analytical techniques and DFT results suggest that the unique N-coordinated diatomic Fe-Co (FeCoN6) serves as highly catalytically active sites in Fenton-like reaction, while the neighboring pyrrolic N act as adsorption site for the adsorption of target organic molecules. The ultra-high catalytic performance of diatomic Fe-Co catalysts can be ascribed to its fantastic isolated FeCoN6 configuration and pyrrolic N adsorption site, which greatly shorten the migration distance from reactive radical to the adsorbed organic molecules.

Structural Features of Porous CoFe Nanocubes and Their Performance for Oxygen‐involving Energy Electrocatalysis

AbstractThe structural properties of CoFe composites fabricated from inexpensive Co(II) and Fe(III) precursors using a Prussian blue analogue (PBA) strategy without additional reductants were investigated. Microporous CoFe‐200 and microporous/mesoporous CoFe‐550 structures of the CoFe catalysts (CoFe‐PBA) were produced by calcination for 1 h in N2 at 200 °C or 550 °C, respectively. The electrocatalytic activities of the CoFe catalysts produced for the oxygen evolution and reduction reactions (OER/ORR) were studied in alkaline media. The OER measurements revealed the CoFe‐200 catalyst to be superior to CoFe‐PBA and CoFe‐550, and even surpass the activity of commercial Ir/C in terms of the overpotential at 10 mA cm−2 and onset potential ( ). On the other hand, the ORR activity of CoFe‐550 exhibited a more positive half‐wave potential (0.837 V vs. RHE) and (0.942 V vs. RHE) than CoFe‐200. The Tafel slope (−55.9 mV dec−1) of CoFe‐550 was lower than that of Pt/C (−77.8 mV dec−1). A comparison of CoFe‐200 and CoFe‐550 suggested that the microporosity of CoFe‐200 (average pore diameter, d≤2 nm) was beneficial in terms of the OER. In contrast, the mesoporous (d≈35.6 nm) structure of CoFe‐550 promoted the mass‐transport kinetics of oxygen through the electrode surface. CoFe nanocubes with tunable porosity are potential catalysts that can be utilized selectively for the OER and ORR.