Electrocatalyst For Methanol Oxidation Research Articles

PtPd @CeO2 nanoparticles highly dispersed on carbon nanotubes as efficient electrocatalysts for methanol oxidation

Pt-based alloys have garnered significant attention due to its high electro-catalytic activity and stability. In this study, CeO2 nanoparticles were uniformly loaded onto carbon nanotube. Pt-Pd alloy particles were electrodeposited onto CeO2 nanoparticles to form Pt-Pd@CeO2/carbon nanotubes composites (Pt-Pd@CeO2/CNTs). Performance characterization results showed that Pt1Pd1.8@CeO2/CNTs electrocatalyst exhibited outstanding mass activity (2521 mA·mg Pt+Pd−1) for MOR, which was 7.9 times higher than that of Pt/C catalyst. The synergistic effect of Pt-Pd substantially enhanced the activity and the active oxygen-containing substances of CeO2 effectively improved the anti-CO poisoning ability. This work has provided a new pathway for developing high-performance catalytic catalysts for MOR.

Enhanced methanol electrooxidation catalysis via dual modulation of PtCu alloy and oxygen vacancies

Achieved by introducing defect sites, enhances both the catalytic activity and stability of catalysts. This is crucial for advancing key applications in energy conversion and environmental protection. Here, we introduce a novel Pt-Cu@CeO2/MWCNTs electrocatalyst prepared by dual modulation of the oxygen vacancy anchoring point and the center of the alloying d-band. This catalyst significantly boosts the rate of methanol oxidation. The Pt-Cu@CeO2/MWCNTs catalyst demonstrates a mass activity 3.7 times higher than that of commercial Pt/C, along with exceptional durability. The electron transfer between the PtCu alloy and the oxygen vacancies effectively modulates the d-band center of Pt, leading to a “volcano” relationship between the catalyst’s mass activity and the d-band center. This study advances the development of methanol electrooxidation catalysts by introducing a novel “double enhancement effect” model.

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.

New type nanocomposite based on metal-organic frameworks decorated with nickel nanoparticles as a potent electrocatalyst for methanol oxidation in alkaline media

Methanol oxidation reaction (MOR) is used to provide electrical energy via direct methanol fuel cell (DMFC), which requires a practical design of electrocatalysts to accelerate the sluggish MOR. In this study, we successfully fabricated the carbon black nanoparticles/graphite ceramic electrode (CBNPs/GCE) supported metal-organic frameworks (MOFs) and decorated with nickel nanoparticles (NiNPs) as a new type nanocomposite modified electrode (NiNPs/MOFs/CBNPs/GCE) via a chemical and an electrochemical process, respectively. The surface morphology and structure of the synthesized nanocomposite materials and modified electrodes were characterized using field emission scanning electron microscopy, energy dispersive X-ray analysis, Fourier transform infrared spectroscopy, X-ray diffraction and thermogravimetric analysis. Then, the NiNPs/MOFs/CBNPs/GCE was used as a non-platinum electrocatalyst for electrocatalytic oxidation of methanol in alkaline media. The obtained results show the efficient electrocatalytic activity of the NiNPs/MOFs/CBNPs/GCE toward the MOR with high anodic peak current density (Jpa = 34.8 mA cm−2) compared with the other prepared electrocatalysts; MOFs/CCE, NiNPs/CCE, MOFs/CBNPs/GCE, NiNPs/CBNPs/GCE, and NiNPs/MOFs/CCE, due to the synergistic effect of nanocomposite components; NiNPs, MOFs and CBNPs. The prepared electrocatalyst; NiNPs/MOFs/CBNPs/GCE, not only shows a high electrochemically active surface area (ECSA = 2.15 cm2) but also has long-term durability in MOR. In general, it can be said the NiNPs/MOFs/CBNPs/GCE is a promising candidate for application in DMFC.

MoO3/WO3/rGO as electrode material for supercapacitor and catalyst for methanol and ethanol electrooxidation.

The potential of metal oxides in electrochemical energy storage encouraged our research team to synthesize molybdenum oxide/tungsten oxide nanocomposites (MoO3/WO3) and their hybrid with reduced graphene oxide (rGO), in the form of MoO3/WO3/rGO as a substrate with relatively good electrical conductivity and suitable electrochemical active surface. In this context, we presented the electrochemical behavior of these nanocomposites as an electrode for supercapacitors and as a catalyst in the oxidation process of methanol/ethanol. Our engineered samples were characterized by X-ray diffraction pattern and scanning electron microscopy. As a result, MoO3/WO3 and MoO3/WO3/rGO indicated specific capacitances of 452 and 583 F/g and stability of 88.9% and 92.6% after 2000 consecutive GCD cycles, respectively. Also, MoO3/WO3 and MoO3/WO3/rGO nanocatalysts showed oxidation current densities of 117 and 170 mA/cm2 at scan rate of 50 mV/s, and stability of 71 and 89%, respectively in chronoamperometry analysis, in the MOR process. Interestingly, in the ethanol oxidation process, corresponding oxidation current densities of 42 and 106 mA/cm2 and stability values of 70 and 82% were achieved. MoO3/WO3 and MoO3/WO3/rGO can be attractive options paving the way for prospective alcohol-based fuel cells.

Facile Synthesis of PtP2 Nanocrystals as Highly Active Electrocatalysts for Methanol Oxidation.

Although significant efforts have been made in the past few decades, the development of affordable, durable, and effective electrocatalysts for direct methanol fuel cells (DMFCs) remains a formidable challenge. Herein, we present a facile and efficient phosphorization approach for synthesizing PtP2 intermetallic nanocrystals and utilize them as electrocatalysts in the methanol oxidation reaction (MOR). Impressively, the synthesized PtP2 nanocatalysts exhibit a mass activity of 2.14 mA μg-1 and a specific activity of 6.28 mA cm-2, which are 5.1 and 9.5 times higher than those achieved by the current state-of-the-art commercial Pt/C catalyst, respectively. Moreover, the PtP2 nanocatalysts demonstrate improved stability toward acidic MOR by retaining 92.1% of its initial mass activity after undergoing 5000 potential cycles, far surpassing that of the commercial Pt/C (38%). Further DMFC tests present a 2.7 times higher power density than that of the commercial Pt/C, underscoring their potential for application in methanol fuel cells. Density functional theory calculations suggest that the accelerated MOR kinetics and improved CO tolerance on PtP2 can be attributed to the attenuated binding strength of CO intermediates and the enhanced stability due to strong Pt-P interaction. To our knowledge, this is the first report identifying the MOR performance on PtP2 intermetallic nanocrystals, highlighting their potential as highly active and stable nanocatalysts for DMFCs.

Chrysanthemum‐Flowers‐Like Bimetal Oxide Based Electrocatalyst for Methanol Oxidation Reaction

Transition metal oxides have garnered attention for the methanol electro‐oxidation reaction owing to their easy availability, high catalytic applicability, and multiple oxidation capabilities. Bimetal‐based catalysts further enhance the performance of the methanol oxidation reaction. In this context, a chrysanthemum‐flower‐like MoO2/WO3 is synthesized through a solvothermal and annealing strategy. The morphology attests to the rough surface and pores in the catalyst, augmenting its surface area for reactions and enhancing catalytic applicability. Electrochemical oxidation of methanol yields an optimal current density of 0.99 mA cm−2 and 2.07 mA mg−1 at a potential of 0.57 V versus Ag/AgCl. The catalyst exhibits a remarkably low Tafel slope of 37.45 mV dec−1, affirming its rapid reaction kinetics. Electrochemical impedance spectroscopy (EIS) reveals an equivalent electronic circuit of R(Q(R(QR)Q(RW))), confirming low charge transfer resistance (Rct) and diffusion‐controlled kinetics attributable to the pores in the sample. The sample also demonstrates an electrochemically active surface area (ECSA) value equal to 0.122 mF cm−2 and long‐term stability over continuous 5000 s, exhibiting no change and high resistance to CO poisoning. All these characterizations and obtained results collectively affirm that the chrysanthemum‐flower‐like MoO2/WO3 serves as a highly suitable electrocatalyst for the electrochemical oxidation of methanol.

Microwave Assisted Synthesis of PtxRu1−x-NiTiO3: A Novel Hybrid Nanostructured Electrocatalyst for Direct Methanol Oxidation

In the present investigation, we have explored the preparation of PtxRu1-x-NiTiO3 hybrid electrocatalysts for the application of methanol oxidization. The XRD and Raman analysis of PtxRu1-x-NiTiO3 confirmed the rhombohedral crystal structure of NiTiO3 and cubic-structured Pt(Ru) nanoparticles. TEM analysis signifies that Pt(Ru) nanoparticles is decorated on the surface of the NiTiO3. The mean size of the Pt(Ru) nanoparticles calculated from the TEM profile is around 2 nm which corroborates with the crystallite size estimated from XRD. The XPS analysis confirms the presence of metallic Pt along with its oxidized components (Pt2+ and Pt4+). The cyclic voltammetry analysis evidence that Pt0.5Ru0.5-NiTiO3 has shown better activity in methanol oxidation compared with the other compositions of PtxRu1−x-NiTiO3 along with the maximum current density of 65.41 mA cm−2 with less carbon poisoning. Chronoamperometry and polarization studies represent the stability and electrochemical activity of the Pt0.5Ru0.5-NiTiO3 electrocatalysts towards methanol oxidation. Based on the research carried out in this work, it is concluded that the PtxRu1−x-NiTiO3 would be a promising candidate as an electrocatalyst for methanol oxidation in direct methanol fuel cells.

Research on preparation of high activity and durable carbon-supported platinum catalyst for methanol electro-oxidation by a facile continuous microwave pipeline method

In methanol oxidation reaction (MOR), it is crucial for the catalyst that Pt particles uniformly cover the surface of the carrier and the Pt surface active sites can effectively remove the binding with CO. This article develops a simple and effective continuous microwave technology. Carbon loaded nano platinum was synthesized by rapidly and uniformly heating a ethylene glycol mixture containing carbon black (CB) H2PtCl6 using microwave radiation, with a Pt content of 49.5%. The experimental results indicate that platinum particles are uniformly loaded onto the carbon surface, with uniform shape and size, and an average particle size of 3.02 nm. And the Pt/C catalyst prepared by continuous microwave technology showed enhanced electrocatalytic activity (peak current density of 76.95 mA/cm2) in MOR after heating at appropriate temperature in N2 atmosphere, which exceeded the commercial catalyst TKK (47.07 mA/cm2) by 63.6%. And the catalyst's resistance to CO toxicity and durability; Higher than commercial Pt/C catalysts. Compared with traditional methods, continuous microwave technology exhibits higher energy utilization efficiency and faster reaction speed in the catalyst preparation process. This technology also has the ability to achieve continuous preparation, which is one of the effective technological approaches to achieve large-scale catalysts production.

Pt loaded on 3D micro-flower-shaped NiFe layered double hydroxides as a highly active and durable methanol oxidation electrocatalyst

The search for CO-resistant methanol oxidation reaction (MOR) catalysts for direct methanol fuel cells (DMFC) is an important yet difficult task. The synergy materials Pt and M (M = Co, Fe, Ni, and Ru et al.) considerably enhance CO-stripping by synergistic oxidation (Pt-COads + 2 M−OHads → Pt + 2 M + H2O + CO2). However, these M materials do not presently attain the optimum CO-stripping efficiency and lack screening procedures, thus their durability falls well short of DMFC requirements. Here, we generalize the relationship between the M−OHads generation ability and Pt-COads effect by examining the OER activity and MOR durability. This allows us to screen ideal M materials, ensures CO-stripping efficiency, and helps in identifying the intrinsic OER mechanism to the MOR durability. A Pt-modified 3D micro-flower-shaped layered double hydroxides (NiFe-LDH) was designed in this study. Under the modification of OER activity, the MOR catalytic mass activity of Pt/NiFe-LDH reaches 3288.7 mA mg-1Pt. More importantly, because of the NiFe-LDH synergy, the CO-poisoned Pt could be reactivated using a simple CV method, and the reactivated Pt/NiFe-LDH could maintain four times or more CA tests with low activity loss. Such a type of M materials screening approach focuses on not only Pt/NiFe-LDHs reported in this work but also the design of Pt/Pd-based MOR catalysts on DMFCs.

NiCoMo nanoparticles as an efficient electrocatalyst for methanol electro‐oxidation in alkaline media

AbstractUsing the electrospinning approach, various percentages of less expensive metal alloy‐decorated nanofiber catalysts have been successfully made as a substitute for platinum in direct methanol fuel cells (DMFC). This work focuses on the synthesis and characterization of catalysts with metal fixed ratio of 20% wt for DMFC applications, specifically Ni/CNFs, Co/CNFs, and NiCoMo/CNFs. The catalysts are characterized using various techniques, including x‐ray diffraction, scanning electron microscope, transmission electron microscopy, energy dispersive x‐ray, and electrochemical measurements. All the prepared samples, regardless of the metal concentration, had good nanofiber form and a distinct nanoparticle appearance, according to the scanning electron microscope (SEM). Chromatography, scan rate, response time, and cyclic voltammetry all were used to examine the samples' ability to perform methanol electrocatalysis. When Mo is added to Ni with Co, the electrooxidation reaction's activation energy and electrode stability both increase. With a starting potential of 0.22 V, the maximum current density in the NiCoMo/CNF sample was 99.8 mA/cm2 at 0.6 V. To electrooxidize methanol, our electrocatalysts combine diffusion control with kinetic‐limiting processes. This work has shown how to create an effective NiCoMo based methanol electrooxidation catalyst using a special technique.

Nanoarchitectonics for modulation on the electronic structure of ultrafine PtRuFe nanowires as robust methanol electrooxidation catalysts

The widespread adoption of Pt-based electrocatalysts in the anode side of direct methanol fuel cell (DMFC) faces challenges stemming from their limited activity, stability, and high cost. Herein, ultrafine PtRuxFey trimetallic nanowires (PtRuxFey NWs) with a diameter of approximately 1.25 nm were synthesized for the electrocatalytic methanol oxidation reaction (MOR). The structure-activity relationship between the electronic structure of PtRuxFey NWs and their electrocatalytic performance was established by meticulously controlling the addition of Ru(acac)3 and Fe(Ac)2. Under optimal conditions, PtRu0.25Fe0.14 NWs displayed remarkable MOR performance, boasting the mass activity (1332.3 mA mgPt−1) and specific activity (1.0 mA cm−2), a 4.0-fold and 1.8-fold enhancement over that of the commercial catalysts. Additionally, after a chronoamperometry test, PtRu0.25Fe0.14 NWs demonstrated a current density 8.3 times higher than that of Pt/C under the same test conditions. The excellent MOR performance of PtRuxFey NWs can be attributed to their one-dimensional and ultrafine structure advantages, the electronic effects of Ru/Fe on Pt, and the bifunctional capabilities. Our research may lead to a simple and controllable strategy that combines various approaches to enhance the performance of Pt-based electrocatalysts in the anode of DMFC.

Scalable production of bifunctional ordered PtFe alloy electrocatalysts for efficient methanol oxidation and hydrogen evolution

Sub-5 nm sized ordered PtFe alloys encapsulated with thin N-doped carbon (NC) shells exhibit remarkable electrochemical performance both toward methanol oxidation and hydrogen evolution reactions.

Electronic Structure Effect of PtCo Alloy with Adjustable Compositions for Efficient Methanol Electrooxidation.

Various efficient strategies have been developed to overcome the anodic electrocatalyst issue of methanol-based fuel cells owing to their complicated methanol electrooxidation mechanism. In this work, PtCo nanoparticles with adjustable compositions supported on multiwalled carbon nanotubes (Pt1Cox/MWCNTs) through the adsorbing-coating-annealing-etching route were synthesized. Compared with the Pt/C catalyst, Pt1Co3/MWCNTs exhibit better electrocatalytic MOR activity in both activity and durability. Notably, the electrochemical mass and specific activity of the as-prepared catalyst are 1.04 mA μg-1Pt and 2.18 mA cm-2, respectively, which are higher than those of the Pt/C catalyst. Moreover, the as-prepared sample revealed lower onset potential during the CO stripping test. Furthermore, the Pt1Co3/MWCNTs possess a lower current density decrease rate in chronoamperometry and cyclic durability tests. The enhancement of activity and stability of Pt1Co3/MWCNTs could be ascribed to their ordered morphological structure, the electronic interaction between MWCNTs and PtCo nanoparticles, and the suitable electronic structure effect between Pt/Co ratios. The concept of the catalyst design in this study offers a different guideline for constructing the novel methanol electrooxidation catalyst, which will accelerate the widespread fuel cell practical application.

Transition Metal (Ni/Cu) Based Bimetallic Catalyst for Glycerol Oxidation

Alcohol fuel cell is considered as one of the most promising green energy generation option. Glycerol can be used as a potent fuel because of its excellent energy density, ready availability, financial viability and minimal toxicity. Moreover, glycerol is also an active petroleum by-product. In direct glycerol fuel cell, precious noble metal based catalyst was extensively used as electro-catalyst for glycerol oxidation. The use of noble metal as catalysts restricted the viable commercialisation due to its high cost. This study intended to use transition metal such as nickel and copper based monometallic and bimetallic catalyst for glycerol oxidation to lower down the cost of commercialisation. These metals already proved to be efficient catalyst for electro-oxidation of methanol and ethanol [1-2]. Carbon was already proved to prominent support material for electro-catalyst due to high surface area and superior conductivity.The metals were impregnated into carbon support followed by reduction under H2/Ar environment with 20 wt % metal loading. The weight ratio of Ni and Cu in bimetallic catalyst was fixed as 1:1. The average metal particle size of the catalysts varied between 7.8 to 16.3 nm. The cyclic voltammetry of different catalysts for 0.5 M glycerol oxidation in 1 M KOH is shown in Fig 1a). The onset potential of bimetallic catalyst (NiCu/C) was reduced to 0.20 V compared to their monometallic counterpart (0.39 V for Ni/C and 0.42 for Cu/C). The glycerol oxidation peak was observed at 0.71, 0.73 and 0.78 V for Cu/C, Ni/C and NiCu/C respectively. The specific activity and mass activity was shown in Fig 1b). The highest specific (76 mA/cm2) and mass activity (775 mA/mgmetal) was obtained for NiCu/C from glycerol oxidation. The obtained electrochemical surface area (ECSA) was highest for NiCu/C (99 m2/g) followed by Ni/C (44 m2/g) and Cu/C (34 m2/g). The higher activity of NiCu/C could be attributed to the lower Tafel slope, higher ECSA and charge transfer co-efficient. The EIS results conveyed that electro-oxidation process was slower than charge transfer process. Moreover, lowest time constants for the both the process was observed for NiCu/C catalyst. Hence, NiCu/C proved to be efficient electro-catalyst with superior activity for glycerol oxidation in direct glycerol fuel cell. Fig 1. a) Cyclic voltammetry of different catalyst in 0.5 M glycerol and 0.1 M KOH and b) Specific and mass activity of different catalyst.

(Invited) Transforming Metal-Containing Secondary Resources into Functional Materials for Electrochemical Energy Applications

Transforming metal-containing waste into functional materials for electrochemical energy applications presents an innovative and sustainable solution to address the growing issue of waste management and resource conservation. By utilizing end-of-life products, off-specification materials, waste materials, and spent materials as secondary resources, this approach can effectively reduce environmental impacts and promote the development of clean energy technologies.Gas-diffusion electrocrystallization (GDEx) is a novel electrochemical technology that can be used as a step to selectively recover and convert valuable metals from metal-containing waste streams into functional materials for electrochemical energy applications. By leveraging the electrochemical reduction of gases, such as O2 or CO2, for the in-situ production of oxidizing (H2O2) or reducing agents (H2 and CO)—which may also result in the formation of other chemical species, e.g., alkali (OH–) in aqueous media, GDEx facilitates the precipitation of soluble metal precursors. This process results in the formation of metal nanoparticles with controlled compositions, crystal structures, sizes, morphologies, and compositions, tailored for specific electrochemical applications.In this talk, the principles of the GDEx process will be explained and examples will be provided of its applicability in the direct transformation of metals contained in secondary resources for the production of functional materials for electrochemical applications. Specifically, the production of electrocatalysts for methanol oxidation from the recycling of automotive catalysts leachates will be conveyed, as well as the production of active battery materials for Li-ion batteries, and the recovery of lithium from geothermal brines.Gas Diffusion Electrocrystallization (GDEx) is a novel and sustainable approach to transform waste materials into functional materials for electrochemical energy applications. This innovative method enables the recovery and synthesis of valuable metal nanoparticles (NPs) from waste streams, such as end-of-life products and industrial leachates, for use in electrocatalysis, energy storage, and fuel cells.GDEx will be conveyed as a sustainable and scalable technology for the recovery of critical metals, contributing to a circular economy and reducing the environmental impact of mining and refining activities. The opportunity for producing materials with enhanced performance will be portrayed, together with the portent of a customizable and flexible solution which can be integrated with existing recycling chains.AcknowledgementThis research has received funding from the European Union’s Horizon 2020 and Horizon Europe research and innovation programmes under grant agreements 958302 (PEACOC Project), 101069685 (Rhinoceros Project), 101069644 (LICORNE Project), 101058163 (CRM-Geothermal Project), and 101091715 (FIREFLY Project).ReferencesPrato M.R.A., Van Vught V., Chayambuka K., Pozo G., Eggermont S., Fransaer J., Dominguez-Benetton X. (2020) Synthesis of material libraries using gas diffusion electrodes. J. Mater. Chem. A, 8:11674-11686. DOI:10.1039/D0TA00633E.Martinez Mora O., Pozo G., Leon-Fernandez L.F., Fransaer J., Dominguez-Benetton X. (2023) Synthesis of platinum group metal nanoparticles assisted by CO2 reduction and H2 cogeneration at gas-diffusion electrodes. RSC Sustain., 2023, Accepted Manuscript. DOI: 10.1039/D3SU00046J

Electrodeposition of Cu Nanocubes in the Presence of Cl- and Br-

Electrodeposition is one of the simple methods for fabricating metal and alloy thin films. Electrodeposition is performed by applying external electrical energy to conductive substrates immersing in electrolytes containing metal precursors. Metal ions or complexes are reduced on a substrate surface and form metal films. The properties of metal thin films and surface morphology of the electrodeposit can be modulated by the parameters of electrodeposition, the composition of electrolytes, i.e., the concentrations of metal precursors and additives. Furthermore, the atomic composition of alloy films can also be easily controlled by electrochemical parameters in the electrodeposition process.1 As explained, the electrodeposition process has various advantages in producing metal thin films with desired properties. However, creating nanostructures with precisely controlling their shapes in the nm scale is relatively difficult. In colloidal syntheses, various nanocrystals, including nanowires, nanospheres, octahedrons, nanocubes, and nanoplates, can be obtained by introducing shape-directing agents.2-4 In the case of electrodeposition, the template-assisted electrodeposition method is the most common to form nanostructures,5,6 and relatively few examples of shape controlling by additives have been reported. Although the formation of metal nanowires in the presence of 3,5-diamino-1,2,4-triazole (DAT) has been recently reported,7 shape control of metal deposits by additives during the electrodeposition process is still limited to few nanostructures. Electrodeposition induces metal growth relatively faster than colloidal synthesis, and a precise nucleation step is not involved in the electrodeposition, which is critical in colloidal syntheses. In this study, we have adopted pulse-reverse electrodeposition to modulate metal nucleation at the initial stage of electrodeposition and also maximize the effects of additives. Pulse-reverse electrodeposition has been researched for controlling the properties of metal thin films and changing the adsorption of additives.8,9 Therefore, pulse-reverse electrodeposition can catch up with the shape control in colloidal syntheses. This presentation will introduce how the parameters in pulse-reverse electrodeposition and additives (halide ions) affect the shape of Cu nanocrystals. References 1) T. P. Moffat, J. J. Mallett, and S. M. Hwang, “Oxygen Reduction Kinetics on Electrodeposited Pt, Pt100− x Nix , and Pt100−xCox” J. Electrochem. Soc. 156, B238 (2009)2) Y. Xia, Y. Xiong, B. Lim, and S. E. Skrabalak, “Shape-Controlled Synthesis of Metal Nanocrystals: Simple Chemistry Meets Complex Physics?” Angew. Chem. Int. Ed. 48, 60 (2009)3) K. A. Fichthorn, Z. Chen, Z. Chen, R. M. Rioux, M. J. Kim, and B. J. Wiley, “Understanding the Solution-Phase Growth of Cu and Ag Nanowires and Nanocubes from First Principles” Langmuir 37, 4419 (2021)4) D. Huo, M. J. Kim, Z. Lyu, Y. Shi, B. J. Wiley, and Y. Xia, “One-Dimensional Metal Nanostructures: From Colloidal Syntheses to Applications” Chem. Rev. 119, 8972 (2019)5) K. R. Yeo, J. Y. Eo, M. J. Kim and S.-K. Kim, “Shape Control of Metal Nanostructures by Electrodeposition and their Applications in Electrocatalysis” J. Electrochem. Soc. 169, 112502 (2022)6) C. Liu, Z. Li, P. Yu, H. W. Wong, and Z. Gu, “Vertically Aligned and Surface Roughed Pt Nanostructured Wire Array as High Performance Electrocatalysts for Methanol Oxidation” ACS Appl. Energy Mater. 1, 3973 (2018)7) T. T. H. Hoang, S. Ma, J. I. Gold, P. J. A. Kenis, and A. A. Gewirth “Nanoporous Copper Films by Additive-Controlled Electrodeposition: CO2 Reduction Catalysis” ACS Catal. 7, 3313 (2017)8) M. J. Kim, T. Lim, K. J. Park, S. K. Cho, S.-K. Kim, and J. J. Kim “Characteristics of Pulse-Reverse Electrodeposited Cu Thin Films: I. Effects of the Anodic Step in the Absence of an Organic Additive” J. Electrochem. Soc. 159, D538 (2012)9) M. J. Kim, T. Lim, K. J. Park, O. J. Kwon, S.-K. Kim, and J. J. Kim “Characteristics of Pulse-Reverse Electrodeposited Cu Thin Film: II. Effects of Organic Additives” J. Electrochem. Soc. 159, D544 (2012) Figure 1

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.

General Method for Trimetallic Platinum–Cobalt–Rare Earth Alloys on Nitrogen-Doped Carbon as Efficient Methanol Electrooxidation Catalysts

General Method for Trimetallic Platinum–Cobalt–Rare Earth Alloys on Nitrogen-Doped Carbon as Efficient Methanol Electrooxidation Catalysts

Copper selenide - Porous carbon derived from metal-organic frameworks as an efficient electrocatalyst for methanol oxidation

In the present study, a metal-organic framework (Cu-MOF) was used as the precursor for synthesis of carbon-encapsulated copper selenides (namely, Cu2-xSe@PCs). After carbonization of Cu-MOF to Cu/Cu2O@PCs, the selenidation process was applied by selenium powder at 500 °C to form Cu2-xSe@PCs. Scanning electron microscopy showed the maintenance of the initial octahedral structure of Cu-MOF after carbonization and selenidation. Nickel foam (NF) was modified with the prepared composite and used as anode in electrochemical cells. Cyclic voltammetric study in alkaline solution (in the absence of methanol) showed highly increased peak currents (∼4 times) on Cu2-xSe@PCs/NF compared to that on Cu/Cu2O@PCs/NF. The electrocatalytic oxidation of methanol in alkaline solution showed lower overpotential and much higher catalytic currents (629.3 mA cm−2 in methanol 0.5 M) on Cu2-xSe@PCs/NF compared to that on Cu/Cu2O@PCs/NF (204.6 mA cm−2). The long-term stability of the proposed electrocatalyst was studied by chronopotentiometry and chronoamperometry. High potential stability was observed when a constant current (22.3 mA cm−2) was drawn from the cell (>4 h). Similar stability was observed for the catalytic current when a constant voltage (1.62 V vs. RHE) was imposed on the electrode in chronoamperometry. In addition, more than 88.5 % of the catalytic current remained after the application of 300 consecutive potential cycles to Cu2-xSe@ PCs/NF in the alkaline solution of methanol. The electrocatalyst was also used in a two-electrode system. Polarization and power density plots showed improved catalytic methanol oxidation by using Cu2-xSe@PCs/NF compared to Cu/Cu2O@PCs/NF. Excellent electrocatalytic properties of the proposed composite towards methanol, long-term stability and the simple synthetic route of the mono-metal electrocatalyst make it a good candidate as the anode of direct methanol fuel cells.