Electrocatalysts For Methanol Oxidation Reaction Research Articles

Competitive coordination-induced assembling of Ni-mof/NiFe-ldh heterostructure for enhanced electrocatalytic methanol oxidation

Direct methanol fuel cells (DMFCs) can permit the utilization of noble-metal-free electrocatalysts, which certainly reduces the cost and accelerates their practical implementation. With the exploration of efficient and economical methanol oxidation reaction (MOR) catalysts, Ni-based nanostructures have been recognized as the most promising MOR catalysts in alkaline media. Herein, we construct a novel heterojunction MOR electrocatalyst composed of Ni-based metal-organic framework (Ni-MOF) and NiFe-based layered double hydroxides (LDHs) through a coordination-induced self-assembly strategy. Owing to the synergic effect between Ni and Fe sites, coupled with the effect of hetero-interface, the resultant Ni-MOF/NiFe-LDH composite exhibits remarkable MOR activity in 0.1 M KOH electrolyte with the oxidation current density (32.66 mA cm−2) is 2.65 and 2.44 times higher than that of the primitive NiFe-LDH and Ni-MOF. The excellent stability of the Ni-MOF/NiFe-LDH electrocatalyst has also been confirmed by long-term chronoamperometry (CA) analysis. Our work paves a facile controllable way for fabricating MOF/LDH heterostructure targets on MOR and underlines its potential to boost energy conversion efficiency through the manipulation of synergic components.

Unveiling the Pivotal Role of dx2-y2 Electronic States in Nickel-Based Hydroxide Electrocatalysts for Methanol Oxidation.

The anodic methanol oxidation reaction (MOR) plays a crucial role in coupling with the cathodic hydrogen evolution reaction (HER) and enables the sustainable production of the high-valued formate. Nickel-based hydroxide (Ni(OH)2) as MOR electrocatalyst has attracted enormous attention. However, the key factor determining the intrinsic catalytic activity remains unknown, which significantly hinders the further development of Ni(OH)2 electrocatalyst. Here, we found that the electronic state within antibonding bands plays a decisive role in the whole MOR process. The onset potential depends on the deprotonation ability (Ni2+ to Ni3+), which was closely related to the band center of orbital. The closer of orbital to the Fermi level showed the stronger the deprotonation ability. Meanwhile, in the high potential region, the broadening of orbital would facilitate the electron transfer from methanol to catalysts (Ni3+ to Ni2+), further enhancing the catalytic properties. Our work for the first time clarifies the intrinsic relationship between electronic state and the MOR activities, which adds a new layer of understanding to the methanol electrooxidation research scene.

Unveiling the Pivotal Role of dx2‐y2 Electronic States in Nickel‐based Hydroxide Electrocatalysts for Methanol Oxidation

The anodic methanol oxidation reaction (MOR) plays a crucial role in coupling with the cathodic hydrogen evolution reaction (HER) and enables the sustainable production of the high‐valued formate. Nickel‐based hydroxide (Ni(OH)2) as MOR electrocatalyst has attracted enormous attention. However, the key factor determining the intrinsic catalytic activity remains unknown, which significantly hinders the further development of Ni(OH)2 electrocatalyst. Here, we found that the dx2‐y2 electronic state within antibonding bands plays a decisive role in the whole MOR process. The onset potential depends on the deprotonation ability (Ni2+ to Ni3+), which was closely related to the band center of dx2‐y2 orbital. The closer of dx2‐y2 orbital to the Fermi level showed the stronger the deprotonation ability. Meanwhile, in the high potential region, the broadening of dx2‐y2 orbital would facilitate the electron transfer from methanol to catalysts (Ni3+ to Ni2+), further enhancing the catalytic properties. Our work for the first time clarifies the intrinsic relationship between dx2‐y2 electronic state and the MOR activities, which adds a new layer of understanding to the methanol electrooxidation research scene.

One-Step Synthesis of 3D Graphene Aerogel Supported Pt Nanoparticles as Highly Active Electrocatalysts for Methanol Oxidation Reaction.

Nowadays, two of the biggest obstacles restricting the further development of methanol fuel cells are excessive cost and insufficient catalytic activity of platinum-based catalysts. Herein, platinum nanoparticle supported graphene aerogel (Pt/3DGA) was successfully synthesized by a one-step hydrothermal self-assembly method. The loose three-dimensional structure of the aerogel is stabilized by a simple one-step method, which not only reduces cost compared to the freeze-drying technology, but also optimizes the loading method of nanoparticles. The prepared Pt/3DGA catalyst has a three-dimensional porous structure with a highly cross-linked, large specific surface area, even dispersion of Pt NPs and good electrical conductivity. It is worth noting that its catalytic activity is 438.4 mA/mg with long-term stability, which is consistent with the projected benefits of anodic catalytic systems in methanol fuel cells.. Our study provides an applicable method for synthesizing nano metal particles/graphene-based composites.

CeO2-supported Pt nanoclusters for improved electrochemical oxidation of methanol

Developing highly durable and active Pt-supported catalysts is currently the most prominent and practicable electrocatalyst design strategy for direct methanol fuel cells (DMFC) due to their high electrocatalytic stability and activity. Herein, we fabricated CeO2 nanorods with tiny Pt nanoparticles that possess good electrocatalytic behavior for methanol oxidation reaction (MOR). In addition, the presence of Ce3+ and small Pt nanoparticles (3.46 nm) enhanced strong metal interaction, facilitating the formation of oxygen vacancies on the CeO2 surface to boost the MOR performance. Hence, the Pt-CeO2 catalyst revealed high mass activity (1414.0 mA mg−1) and areal-specific activity (1.615 mA cm−2) towards MOR in an acidic electrolyte, which was three times that of the 20% Pt/C catalyst (545.4 mA mg−1 and 0.856 mA cm−2). Besides, the Pt-CeO2 catalyst exhibited excellent performance of MOR in an alkaline electrolyte and retained 90.44% of its initial mass activity after 5000 cycles due to the unique morphology and synergistic effects between Pt and CeO2. Pt-CeO2 is regarded as a promising MOR electrocatalyst for DMFC applications.Graphical

Mixed-Dimensional Partial Dealloyed PtCuBi/C as High-Performance Electrocatalysts for Methanol Oxidation with Enhanced CO Tolerance.

Developing efficient electrocatalysts for methanol oxidation reaction (MOR) is crucial in advancing the commercialization of direct methanol fuel cells (DMFCs). Herein, carbon-supported 0D/2D PtCuBi/C (0D/2D PtCuBi/C) catalysts are fabricated through a solvothermal method, followed by a partial electrochemical dealloying process to form a novel mixed-dimensional electrochemically dealloyed PtCuBi/C (0D/2D D-PtCuBi/C) catalysts. Benefiting from distinctive mixed-dimensional structure and composition, the as-obtained 0D/2D D-PtCuBi/C catalysts possess abundant accessible active sites. The introduction of Cu as a water-activating element weakens the COads , and oxophilic metal Bi facilitates the OHads , thereby enhancing its tolerance to CO poisoning and promoting MOR activity. The X-ray photoelectron spectroscopy (XPS) and X-ray absorption fine structure spectroscopy (XAFS) collectively reveal the electron transfer from Cu and Bi to Pt, the electron-enrichment effect induced by dealloying, and the strong interactions among Pt-M (Cu, Pt, and Bi) multi-active sites, which improve the tuning of the electronic structure and enhancement of electron transfer ability. Impressively, the optimized 0D/2D D-PtCuBi/C catalysts exhibit the superior mass activity (MA) of 17.68 A mgPt -1 for MOR, which is 14.86 times higher than that of commercial Pt/C. This study offers a proposed strategy for Pt-based alloy catalysts, enabling their use as efficient anodic materials in fuel cell applications.

Multi-dimensional PtRu/Co3O4-Activated carbon Nano-Electrocatalyst: Metal–Support Interaction, and electronic contributions towards methanol electrooxidation in alkaline fuel cells

In this work, we report PtRu alloy system supported on Co3O4-activated carbon (Co3O4-C) prepared by direct reduction of H2PtCl6 and RuCl3 solutions as a highly active and durable electrocatalyst for methanol oxidation reaction. The electrochemical activity of the electrocatalysts was evaluated using electrochemical impedance spectroscopy (EIS), linear sweep voltammetry (LSV), cyclic voltammetry (CV), and chronoamperometry (CA). The formation of PtRu alloy on the Co3O4-C matrix, as well as their electronic interactions, is confirmed by employing X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and X-ray diffraction (XRD) techniques. The electrocatalysts showed distinct electrocatalytic activity in alkaline medium, depending on whether the catalysts contained PtRu alloy and whether they were supported on the hybrid Co3O4-C, proving their unique contributions to the electrocatalytic reaction. Benefiting from the strong metal-support interaction (SMSI) and electronic interaction between Pt and Ru, the PtRu/Co3O4-C displayed a highly efficient electrocatalytic performance with a mass activity of 6709 mAmgPt-1, a substantial improvement compared to the commercial Pt-based benchmark catalyst, which achieved only 212 mAmgPt-1. Furthermore, the PtRu/Co3O4-C showed excellent stability after 10 000 s, high durability after 500 cycles retaining 94 % of current density, and higher tolerance for CO. This enhanced catalytic performance can be attributed to the small nanoparticle sizes, high dispersion, large ECSA of 102.1 m2/g, and the synergy resulting from electronic coupling interactions.

Direct Electrocatalytic Methanol Oxidation on MoO3/Ni(OH)2: Exploiting Synergetic Effect of Adjacent Mo and Ni.

Ni-based materials have been widely investigated as methanol oxidation reaction (MOR) catalysts. The formation of NiOOH and its reduction to Ni(OH)2 are generally regarded as essential steps for methanol oxidation. However, in such an indirect route, the efficiency of proton coupled electron transfer is fundamentally limited by the rate of transition from Ni(OH)2 to NiOOH back and forth. Herein we demonstrate a direct MOR pathway on MoO3/Ni(OH)2 without the formation of a NiOOH mediator. The MoO3/Ni(OH)2 exhibits a benchmark electrocatalytic MOR current density of 1000 mA cm-2 at 1.52 V vs. RHE with a nearly 100% faradic efficiency, outperforming all the state of art MOR electrocatalysts. In-situ Raman spectroscopy confirms that NiOOH is not formed during the electrocatalytic MOR process on the MoO3/Ni(OH)2. Density functional theory calculations suggest that Ni2+ in MoO3/Ni(OH)2 serves as the methanol adsorption site while the doped Mo6+ plays a key role in capturing the deprotonated H·. Benefiting from the Mo-Ni synergistic effect, the energy barrier of the CH2O* → CHO* + H* process is significantly reduced, avoiding the NiOOH formation and leading to the direct MOR. Our research unravels a direct electrochemical MOR pathway that does not rely on NiOOH formation and provides a facile strategy of regulating the intermediate process barrier for MOR.

Assembly of two trinuclear-cluster-based metal-organic frameworks: Structures and methanol electro-oxidation properties

The direct methanol fuel cell (DMFC) is an efficient and non-polluting green energy conversion device. However, the electrocatalysts for the anodic methanol oxidation reaction (MOR) in DMFC are often precious metal catalysts, which suffer from high cost, poor stability, and easy deactivation. In this work, two isostructural metal-organic frameworks (MOFs) [M3(μ3-OH)(TATB)(Nic)2(H2O)2(DMA)] (M = Co, Ni) were successfully synthesized under solvothermal conditions. Both frameworks possess a unique trinuclear cluster [M3(μ3-OH)(COO)5] secondary building unit (SBU) and a rare binodal (3,7)-connected network. Due to the high density of metal sites and prominent pore system within CTGU-36-Ni, it can serve as an effective molecular electrocatalyst for MOR, while CTGU-36-Co is an inert material. Further experimental results showed that the introduction of conductive substances could lead to a significant increase in the MOR area activity of CTGU-36-Ni. This work not only provides a non-noble metal molecular MOR electrocatalyst but also opens a new vision for the design and application of crystalline materials in various energy conversion processes.

NiSe integrated with polymerized reduced carbon sheet: As an effective electrocatalyst for methanol oxidation reaction

A low-energy approach was used to create ternary composites of hollow tubular Poly-N-methyl pyrrole (P-NMPy) and NiSe nanoparticles decorated onreduced graphene oxide (RGO). On the surface of RGO, P-NMPy, and NiSe nanoparticles were uniformly disseminated. The RGO/NiSe@P-NMPy (RNP) polymer nanocomposite was made utilizing a straightforward chemical oxidative process. The RGO/NiSe@P-NMPy nanocomposite was studied using FTIR spectroscopy, UV–visible, XRD, FE-SEM with EDAX, AFM, TEM and electrochemical investigations. The electrocatalytic activity of this polymer nanocomposite for the methanol oxidation reaction in alkaline environments was validated using cyclic voltammetry. The RGO/NiSe@P-NMPy electrocatalyst shows excellent electrocatalytic activity, lower oxidation potential (0.1 V), improved current density (127 mA/cm2), excellent stability and longevity (900 s) towards methanol oxidation reaction (MOR) in alkaline medium. It was observed RGO/NiSe@P-NMPy electrocatalyst, the ECSA value is 70.83 m2/g. This result clearly depicts that RGO/NiSe@P-NMPy electrocatalyst has more active sites for MOR reaction. According to the results, the P-NMPy introduction in RGO/Nickel Selenide structure can enhance the performance of methanol oxidation and increase the resistance to CO in comparison with monometallic catalysts.

The facile production of Fe2O3-biochar electrocatalyst for methanol oxidation reaction

In this study, the facile-green method was applied for the production of electroactive composite anode material. For this purpose, biochar was produced via pyrolysis of Pinus nigra (PN) sawdust in a stainless-steel reactor at 300, 400 and 500 °C with 10 °C/min heating rate. The Fe2O3 particles were fabricated via the green synthesis method. The Fe2O3-biochar electrocatalyst was operated on Ni foam electrode and the potential application as an anode for methanol fuel cell was investigated in an alkaline medium. Field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), X-ray diffraction analysis (XRD), Brunauer-Emmett-Teller analysis (BET), and attenuated total reflectance Fourier transform infrared spectroscopy (FTIR/ATR) were used to characterize the morphology of the electrocatalyst samples. The electrochemical measurements of electrocatalyst samples were achieved via cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), linear sweep voltammetry (LSV) and chronoamperometry (CA). The enlarged surface area of biochar enabled the formation of more electroactive sites for methanol electrooxidation and favorable structures of biochar could support to increased electrocatalytic activity of catalysts for methanol oxidation and produce favorable matrices for Fe2O3 loading. The obtained results demonstrate that the electrooxidation of methanol occurred at 0.36 V. The favorable structures of biochar acted as a support, enhancing the electrocatalytic activity of Fe2O3 for methanol oxidation. The electrocatalyst demonstrated remarkable activity with almost 4 A g−1 current density at 0.55 V. The Rct values were 0.73 Ω and 0.45 Ω at 0.55 V, for Ni foam and Ni foam/Fe2O3-biochar, respectively. Long-term measurements demonstrated that the Ni foam/Fe2O3-biochar catalysts was remarkably stable, with a 4 % difference in current before and after the CA analysis.

Binder-free cobalt molybdate nanoflakes grown on nickel foam as a hybrid supercapacitor and electrocatalyst for methanol oxidation reaction

In this work, Cobalt molybdate nanoflakes were grown on nickel foam which is used as an electrode for the supercapacitor and electrocatalyst for the methanol oxidation reaction. XRD, Raman, and XPS analysis further confirm the formation of CoMoO4. FESEM image shows that the CoMoO4 nanoflakes with a thickness of ∼91 nm and diameter of ∼1 µm were formed. In a three-electrode system, CoMoO4/NF exhibited a capacitance (capacity) of 359.8 F g−1 (215.88 Cg−1). CoMoO4/NF retained 73.8 % of capacitance after 9500 cycles with 89.4 % of coulombic efficiency. After a long cycle, the electrode undergoes XPS and FESEM analysis. From XPS, its major oxidation state was changed from 2+ to 3+ and Mo was leached out from the electrode. FESEM analysis showed that nanoflake size decreased to 53.34 nm from 91 nm. The aqueous hybrid supercapacitor (HSC) exhibited a capacitance of 86 F g−1 at 1 A g−1. Aqueous HSC exhibited an energy density of 17.5 Wh Kg−1 and a power density of 2970 W Kg−1. CoMoO4/NF showed good oxidation properties towards methanol to carbon dioxide. After the 1000 cycles, the forward oxidation peak shifted to −0.052 V from −0.00884 V vs Hg/HgO. After the 1000 cycles, a 46 % decrease in methanol oxidation current is observed.

RGO@Ni/NiO composite an effective electrocatalyst for methanol oxidation reaction in alkaline media

A composite comprised of reduced graphene oxide and nickel/nickel oxide (rGO@Ni/NiO) was synthesized and used as a modifier to fabricate a modified carbon paste electrode (CPE-rGO@Ni/NiO) for the methanol oxidation reaction (MOR) in alkaline medium. The fabricated CPE-rGO@Ni/NiO showed a pronounced electrocatalytic activity towards methanol oxidation at the potential of about 0.58 V vs. Ag|AgCl|KClsat. The effect of experimental parameters on the electrocatalytic activity of the prepared electrode towards MOR was explored in alkaline medium. The results of hydrodynamic chronoamperometry using the fabricated electrode showed enhanced stability towards MOR at the applied potential of 0.580 V for 11 h. The enhanced stability was attributed to the presence of rGO that not only provides a large conductive surface area with a high electron exchange property to accumulate Ni/NiO but also increases CO-tolerance to resist more towards intermediates.

Enlightening the performance-boosting effect of electroactivation approaches on the electrooxidation of methanol reaction in acidic media catalyzed by cobalt-tin bimetallic nanocatalysts

This research investigates the impact of electrochemical activation on cobalt-tin (Cox-Sn100-x) bimetallic nanocatalysts for the methanol oxidation reaction (MOR) in acidic conditions. Two electroactivation protocols, namely activation in a phosphate buffer (PB) solution and in-situ activation, using chronoamperometry, were developed. The electrochemical performance of the MOR electrocatalyst was evaluated through cyclic voltammetry analysis within a specific electrode potential range. Optimal activation conditions for the PB solution were achieved at a pH of 3.0 and an activation potential of −1.3 V (vs. Ag/AgCl), while the in-situ activation process showed the best results at an activation potential of −0.7 V (vs. Ag/AgCl). Both the in-situ and PB electroactivated Co65–Sn35 catalysts exhibited significant enhancements in MOR activity, with the in-situ activation resulting in a 10-fold increase and the PB activation leading to an 8.5-fold increase. The proposed mechanism for this substantial enhancement involves simultaneous hydrogen evolution and water electrolysis during the electroactivation treatments of the Co65–Sn35 electrocatalyst. In fact, the formation of OHads species during the electroactivation treatment could provide a fraction of OHads which was essential for the MOR. These findings might present opportunities for the engineering and design of bimetallic noble metal-free nanocatalysts for efficient utilization in high-performance acidic direct methanol fuel cells (DMFCs).

Atomically Dispersed CrOX on Pd Metallene for CO-Resistant Methanol Oxidation.

The effective design and construction of high-performance methanol oxidation reaction (MOR) electrocatalysts are significant for the development of direct methanol fuel cells. But the active sites of the MOR electrocatalysts are susceptible to being poisoned by CO, resulting in poor durability. Herein, we report an atomically dispersed CrOX species anchored on Pd metallene through bridging O atoms. This catalyst shows an outstanding MOR performance with 7 times higher mass activity and 100 mV lower CO electrooxidation potential than commercial Pd/C. The results of operando electrochemical Fourier transform infrared spectroscopy demonstrate the rapid removal of CO* on CrOX-Pd metallene. Theoretical calculations reveal that atomically dispersed CrOX can lower the adsorption energy of CO* on Pd sites and enhance that of OH* through the formation of a hydrogen bond, decreasing the formation energy of COOH*. This work provides a new strategy for improving MOR performance via atomically engineering oxide/metal interfaces.

Interfacial engineering of nickel selenide with CeO2 on N-doped carbon nanosheets for efficient methanol and urea electro-oxidation

The design of low cost, high efficiency electrocatalysts for methanol oxidation reactions (MOR) and urea oxidation reactions (UOR) is a pressing need to address the energy crisis and water pollution. In the present work, we developed Cerium dioxide (CeO2) and nickel selenide (Ni0.85Se) nanoparticles integrated into three-dimensional N-doped carbon nanosheets to be used as efficient and stable bifunctional electrocatalysts for MOR and UOR. By optimizing the selenization temperature, the CeO2-modified Ni0.85Se obtained at selenization temperature of 550 °C (CeO2-Ni0.85Se-550-NC) has the best MOR and UOR electrochemical performance. The CeO2-Ni0.85Se-550-NC potential only requires 1.309 V (MOR) and 1.294 V (UOR) to reach 10 mA cm−2, respectively. The DFT study reveals that CeO2-Ni0.85Se-550-NC has the best reaction path with the synergistic effect between CeO2 and Ni0.85Se. The outstanding catalytic performance of CeO2-Ni0.85Se-550-NC may be due to the cointeraction between CeO2 and Ni0.85Se, allowing more defects that function as catalytic sites while promoting fast electron transfer in the N-doped carbon substrate.

Formation mechanism of macroporous Cu/CuSe and its application as electrocatalyst for methanol oxidation reaction

Single-step solvothermal method is used to prepare Cu/CuSe as an electrocatalyst for methanol electro-oxidation reaction (MOR). 1,3-butan-diol is selected as a reaction medium, whose viscosity and complex formation with Cu(II) ions dictate the catalyst morphology. The catalyst has a macroporous structure, which is composed of nanoballs with a high purity, crystallinity, and uniform morphology. The electrocatalyst is excellent for MOR, as it delivers current density of 37.28 mA/mg at potential of 0.6 V (vs Ag/AgCl) in the electrolyte of 1 M KOH and 0.75 M methanol at a 50 mV/s scan rate under conditions of cyclic voltammetry. The catalyst also shows good stability for 3600 s with negligible charge transfer resistance and high electrochemical active surface area (ECSA) value of 0.100 mF/cm2.

Facile synthesis of PEG-glycerol coated bimetallic FePt nanoparticle as highly efficient electrocatalyst for methanol oxidation

Direct methanol fuel cell (DMFC) has shown excellent growth as an alternative candidate for energy sources to substitute fossil fuels. However, developing cost-effective and highly durable catalysts with a facile synthesis method is still challenging. In this prospect, a facile strategy is used for the preparation of hydrophilic Fe-Pt nanoparticle catalyst via a polyethylene glycol-glycerol route to utilize the advantages of nanostructured surfaces. The synthesized electrocatalysts are characterized by XRD, XPS, TEM, EDS and FTIR to confirm their structure, morphology, composition, and surface functionalization. The performance of the catalysts towards methanol oxidation reaction (MOR) was investigated by cyclic voltammetry and chronoamperometry in both acidic and alkaline media. The Fe-Pt bimetallic catalyst exhibits better current density of 36.36 mA cm−2 in acidic medium than in alkali medium (12.52 mA cm−2). However, the high If/Ib ratio of 1.9 in alkali medium signifies better surface cleaning/regenerating capability of catalyst. Moreover, the catalyst possessed superior cyclic stability of ~ 80% in the alkaline electrolyte which is 1.6 times higher than in the acidic one. The better stability and poison tolerance capacity of catalyst in alkaline media is attributed to the OH− ions provided by the electrolyte which interact with the metal species to form M-(OH)x and reversibly release OH− and regenerate metal surface for further oxidation reactions. But synergism provided by Fe and Pt gives better activity in acidic electrolyte as Pt is favourable catalyst for dehydrogenation of methanol in acidic medium. This study will be useful for designing anodic electrocatalysts for MOR.

Formicary-like PtBi1.5Ni0.2Co0.2Cu0.2 high-entropy alloy aerogels as an efficient and stable electrocatalyst for methanol oxidation reaction

High-entropy alloy aerogels (HEAAs) have become promising electrochemical catalysts because of the advantageous combination of high-entropy alloys and aerogel structure. However, how to fabricate 3D porous high-entropy alloys accurately is still a great challenge due to their inherent thermodynamic instability and differences in reduction potentials of metal ions. Herein, PtBi1.5Ni0.2Co0.2Cu0.2 HEAAs have been synthesized by combining co-reduction method and freeze-drying technology. The resulting PtBi1.5Ni0.2Co0.2Cu0.2 HEAAs have the structural and morphological benefits of both high-entropy alloys and aerogels. Both XPS and DFT results confirm that the d-band center of PtBi1.5Ni0.2Co0.2Cu0.2 HEAAs shifts to lower binding energy compared to Pt/C, indicating the effective regulation of electronic structure on the surface of PtBi1.5Ni0.2Co0.2Cu0.2 HEAAs. As a demonstration in the methanol oxidation reaction (MOR), a mass activity of 4.19 A mgPt−1 and long-term stability (>0.33 A mgPt−1 after 10 cycles of 3600 s stability test) can be obtained on the PtBi1.5Ni0.2Co0.2Cu0.2 HEAAs, outperforming binary Pt-based alloys and commercial Pt/C. The CO adsorption strength of PtBi1.5Ni0.2Co0.2Cu0.2 HEAAs is more weaker than that of PtBi1.5 alloys and Pt/C, which proves the enhanced CO tolerance. The results pave the way for fabricating the hybrids of high-entropy alloys and aerogels with superior activity and stability.

Constructing a CrCoNi medium entropy alloy coordinated Pt ultrathin film as durable electrocatalysts for methanol oxidation reaction

As high-efficiency anode methanol oxidation catalysts, platinum-based materials have always occupied a dominant place since the inception of direct methanol fuel cells (DMFCs). However, because of the strong adsorption of intermediates, Pt-active centers are easily poisoned and induce serious activity loss. Here, we investigate the same commonality of the oxygen evolution reaction (OER) and methanol oxidation reaction (MOR) mechanism in Pt/CrCoNi complex catalysts and establish a relationship between them to help screen appropriate synergistic materials and reduce activity loss. With this strategy, the OER activity of Pt/CrCoNi is modified via temperature and oxygen pressure control, and the OER overpotential and MOR durability show a positive correlation. The MOR performance of the final optimized Pt/CrCoNi (7.5–225 Torr oxygen pressure and 400 °C annealing, OA) film reaches an advanced level in the Pt-based MOR catalysts and shows a mass activity of 3785 A gPt-1, as well as a good durability of 50000 s in the alkaline solution.