mA mgPt Research Articles

Platinum-Ruthenium Bimetallic Nanoparticle Catalysts Synthesized Via Direct Joule Heating for Methanol Fuel Cells.

Platinum-Ruthenium (PtRu) bimetallic nanoparticles are promising catalysts for methanol oxidation reaction (MOR) required by direct methanol fuel cells. However, existing catalyst synthesis methods have difficulty controlling their composition and structures. Here, a direct Joule heating method to yield highly active and stable PtRu catalysts for MOR is shown. The optimized Joule heating condition at 1000°C over 50 microseconds produces uniform PtRu nanoparticles (6.32wt.% Pt and 2.97 wt% Ru) with an average size of 2.0 ± 0.5 nanometers supported on carbon black substrates. They have a large electrochemically active surface area (ECSA) of 239 m2 g-1 and a high ECSA normalized specific activity of 0.295mA cm-2. They demonstrate a peak mass activity of 705.9mA mgPt -1 for MOR, 2.8 times that of commercial 20 wt.% platinum/carbon catalysts, and much superior to PtRu catalysts obtained by standard hydrothermal synthesis. Theoretical calculation results indicate that the superior catalytic activity can be attributed to modified Pt sites in PtRu nanoparticles, enabling strong methanol adsorption and weak carbon monoxide binding. Further, the PtRu catalyst demonstrates excellent stability in two-electrode methanol fuel cell tests with 85.3% current density retention and minimum Pt surface oxidation after 24 h.

N‐doped Porous ZIF@PDA/Pt Catalysts with Ultra‐Low Pt for Methanol Oxidation

AbstractMetal‐organic frameworks (MOFs) materials, due to their unique porous structure, large surface area, low density, and customizable ligands, have the potential to serve as catalytic carriers. They can address the limitations of pure platinum (Pt), including susceptibility to toxicity and poor stability during catalytic processes. In this study, ZIF‐8@ZIF‐67 derived N‐doped carbon‐loaded ultra‐low Pt catalysts (ZIF@PDA/Pt‐x‐y) were prepared using zeolitic imidazolate frameworks (ZIFs) as carriers. Meanwhile, the effects of dopamine hydrochloride (DA) incorporation and reaction temperature on the topography structure and electrocatalytic properties of the synthesized samples were mainly investigated. The introduction of polydopamine (PDA) relieved the loss of the nitrogen source of ZIF due to high temperature. The electrocatalytic performances of synthetic samples for methanol oxidation were investigated using electrochemical methods, and ZIF@PDA/Pt‐5‐900 exhibited the most favorable catalytic effect. Compared to other samples and the Pt/C catalyst (20 %), ZIF@PDA/Pt‐5‐900 demonstrated the largest electrochemically active surface area (ECSA, 66.25 m2 mgPt−1), higher electrocatalytic amount activity (1719.28 mA mgPt−1) and superior stability. Overall, this finding offers a new approach for preparing catalysts for direct methan ol fuel cells (DMFCs).

Pt cluster incorporated NiO nanoflower boosts hydrogen evolution reaction via enhanced metal support interaction

Hydrogen serves as a potent and environment friendly energy source, and developing high performance hydrogen evolution reaction (HER) electrocatalysts is crucial for water splitting. In this work, Pt nanoparticles incorporated NiO nanoflower (Pt-NiO) is synthesized using an ethylene glycol reduction method. The incorporation of Pt not only introduces extra high active sites, but also induces strong interaction between NiO and Pt. Meanwhile, the NiO nanoflower support enables the dispersion of Pt and ensure high electrochemically surface area as well as fast mass transport, which greatly improves catalytic activity of Pt-NiO. Pt-NiO-3 only requires a small overpotential of 26 mV to reach 10 mA cm−2 and the Tafel slope is only 19.49 mV dec−1. In addition, the mass activity can achieve 2000 mA mgPt−1 at an overpotential of 63 mV. Moreover, obvious bubbles can be observed in the assembled H-type for overall water splitting, and the Faraday efficiency is close to 100 %, highlighting the superiority of Pt-NiO-3. This work provides insights for designing high effective electrocatalysts for HER.

Engineering both intrinsic characteristic and local microenvironment of platinum sites toward highly efficient oxygen reduction reaction

The optimization of the adsorption of oxygen-containing intermediates on platinum (Pt) sites of Pt-based electrocatalysts is crucial for the oxygen reduction reaction process. Currently, a large amount of researches mainly focus on modifying the bulk structure of the electrocatalysts, however, the vital role of solvent effect on the phase interfaces is often overlooked. Here, we successfully developed an electrocatalyst in which the ordered PtCo alloy anchors on the cobalt (Co) single-atoms/clusters decorated support (Co1,nNC) and its surface is further optimized using hydrophobic ionic liquid (IL). Experimental studies and theoretical calculations indicate that compressive stress on Pt lattice contributed by intrinsic structure and the local hydrophobicity caused by IL on the surface can suppress the stabilization of *OH on Pt. This synergistic effect affords outstanding catalytic performance, exhibiting a half-wave potential (E1/2) of 0.916 V vs. RHE and a mass activity (MA) of 1350.3 mA mgPt−1 in 0.1 mol/L perchloric acid (0.1 M HClO4) electrolyte, much better than the commercial Pt/C (0.849 V vs. RHE and 145.5 mA mgPt−1 for E1/2 and MA, respectively). Moreover, the E1/2 of IL-PtCo/Co1,nNC only lost 5 mV after 10,000 cyclic voltammetry (CV) cycles due to a strong and synergistic contact of the intermetallic PtCo alloy with the Co1,nNC support and IL. This research provides an effective method for designing efficient electrocatalysts by combining intrinsic structure and surface modification.

Ni-Pt-Pd ternary alloy nanoparticles supported on carboxyl-modified carbon nanotubes as highly efficient catalyst for methanol and ethanol electrooxidation

Pt-based catalysts are currently the most efficient anode catalysts in alcohol fuel cells. However, their widespread commercialization is hindered by their high cost. In this study, a straightforward method was employed to deposit Ni-Pt-Pd ternary alloy nanoparticles onto carboxyl-modified multi-walled carbon nanotubes (CNTs) and subsequently annealed the synthesized catalysts at different temperatures to adjust the surface composition and alloying degree. The Ni-Pt-Pd alloy exhibits a synergistic effect between Pt and Ni. The presence of Ni effectively modulates the d-band center of Pt, thereby enhancing the electrochemical performance of for alcohol oxidation. The synergistic effect of Pt-Pd alloy is harnessed to enhance both catalytic activity and stability of the catalyst for oxidation of methanol or ethanol. Density functional theory (DFT) calculations demonstrated that alloying Pt with Pd and Ni effectively reduced the Gibbs free energy during EOR and MOR reactions. The resulting catalysts, denoted as Ni6Pt6Pd6 NPs/CNTs-M2, exhibited exceptional catalytic oxidation performance for both ethanol and methanol. Specifically, their electrochemical mass activity for ethanol oxidation reaction (EOR) reached 2345 mA mg-1Pt+Pd, which was 15.5-fold and 2.56-fold higher than that of commercial Pt/C and Pd/C catalysts respectively. Moreover, their mass activity for methanol oxidation reaction (MOR) was measured at 2995 mA mg-1Pt+Pd, which was 8.2-fold and 5.3-fold higher than that of Pt/C and Pd/C catalysts respectively.

Atomic controlled shell thickness on Pt@Pt3Ti core-shell nanoparticles for efficient and durable oxygen reduction

The exploitation of durable and highly active Pt-based electrocatalysts for the oxygen reduction reaction (ORR) is essential for the commercialization of proton exchange membrane fuel cells (PEMFCs). Herein, we designed Pt@Pt3Ti core-shell nanoparticles with atomic-controllable shells through precise thermal diffusing Ti into Pt nanoparticles for effective and durable ORR. Combining theoretical and experiment analysis, we found that the lattice strain of Pt3Ti shells can be tailored by precisely controlling the thickness of Pt3Ti shell in atomic-scale on account of the lattice constant difference between Pt and Pt3Ti to optimize adsorption properties of Pt3Ti for ORR intermediates, thus enhancing its performance. The Pt@Pt3Ti catalyst with one-atomic Pt3Ti shell (Pt@1L-Pt3Ti/TiO2-C) demonstrates excellent performance with mass activity of 592 mA mgPt−1 and durability nearly 19.5-fold that of commercial Pt/C with negligible decay (2 %) after 30,000 potential cycles (0.6–1.0 V vs. RHE). Notably, at higher potential cycles (1.0 V-1.5 V vs. RHE), Pt@1L-Pt3Ti/TiO2-C also showed far superior durability than Pt/C (9.6 % decayed while 54.8 % for commercial Pt/C). This excellent stability is derived from the intrinsic stability of Pt3Ti alloy and the confinement effect of TiO2-C. The catalyst’s enhancement was further confirmed in PEMFC configuration.

Optimizing Intermediate Adsorption on Pt Sites via Triple-Phase Interface Electronic Exchange for Methanol Oxidation.

For the most commonly applied platinum-based catalysts of direct methanol fuel cells, the adsorption ability toward reaction intermediates, including CO and OH, plays a vital role in their catalytic activity and antipoisoning in anodic methanol oxidation reaction (MOR). Herein, guided by a theoretical mechanism study, a favorable modulation of the electronic structure and intermediate adsorption energetics for Pt active sites is achieved by constructing the triple-phase interfacial structure between tin oxide (SnO2), platinum (Pt), and nitrogen-doped graphene (NG). From the strong electronic exchange at the triple-phase interface, the adsorption ability toward MOR reaction intermediates on Pt sites could be efficiently optimized, which not only inhibits the adsorption of CO* on active sites but also facilitates the adsorption of OH* to strip the poisoning species from the catalyst surface. Accordingly, the resulting catalyst delivers excellent catalytic activity and antipoisoning ability for MOR catalysis. The mass activity reaches 1098 mA mg-1Pt, 3.23 times of commercial Pt/C. Meanwhile, the initial potentials and main peak for CO oxidation are also located at a much lower potential (0.51 and 0.74 V) against commercial Pt/C (0.83 and 0.89 V).

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.

Effect of tunable composition-shape of bio-inspired Pt NPs electrocatalyst in direct methanol fuel cell: Process optimization and kinetic studies

Highly efficient bio-inspired platinum nanoparticles (Pt NPs) as an electrocatalyst with superior intrinsic kinetics and high performance for methanol oxidation reaction (MOR) derived from green synthesis of bio-waste utilization is of great interest. The bio-inspired Pt NPs were examined for their kinetic parameters in terms of the Tafel plot, exchange current, square root of the scan rate, methanol diffusion coefficient, activation energy (Ea), and factors influencing current density. Bio-inspired Pt NPs exhibit a fast kinetic reaction with a low Tafel value of 179 mV dec−1 and exchange current, α = 0.33, compared to commercial Pt black (233 mV dec−1, α = 0.25). The bio-inspired Pt NPs display low activation energy, Ea, as the potential increases, indicating improved intrinsic kinetics, and the MOR catalyzed by bio-Pt NPs was discovered to be a diffusion-controlled process. The parametric effect of bio-inspired Pt NPs concentration has a crucial influence on the anisotropic morphological structure and interconnection to the current density (mA mg−1) of MOR. Central Composite Design (CCD) was applied for RSM-based modeling and analyzing the parameter effects, including bio-inspired Pt NPs concentration, methanol concentration, and electrocatalyst loading to optimize the current density. The optimized current density produced by bio-inspired Pt NPs was 640.11 mA mgPt−1 at ideal conditions of 1.5 mM bio-Pt NPs, 1.05 M CH3OH, and 2.14 mg. Ultimately, the passive DMFC single-cell powered by bio-inspired Pt NPs generates power density with Pmax of 5.70, 6.67, and 8.28 mW cm−2 at 25, 80, and 100 °C. Thus, bio-inspired Pt NPs derived from green synthesis pathways and biomass-mediated extract have been proven to be viable and sustainable anode electrocatalysts for utilization in the energy conversion of renewable energy with outstanding performance.

PtRu mesoporous nanospheres as electrocatalysts with enhanced performance for oxidation of methanol.

Composition and morphology are crucial factors in the design of Pt-based catalysts with high performance, particularly in direct methanol fuel cells (DMFCs). Herein, PtRu mesoporous nanospheres (PtRu MNs) with tunable compositions were synthesized via a facile method and then deposited on a carbon support to act as electrocatalyst materials for the methanol oxidation reaction (MOR). Superior catalytic activity, better catalytic stability, and good tolerance to CO were achieved by the optimum PtRu (2 : 1) MNs/C catalyst compared with Pt MNs/C. The mass activity on PtRu (2 : 1) MNs/C reached 111.77 mA mgPt -1, which was approximately 6.45-fold higher than that of Pt MNs/C (17.33 mA mgPt -1). Meanwhile, PtRu (2 : 1) MNs/C retained much more current density (84.7%) than Pt MNs/C (17.7%) after 500 cycles. The improved catalytic performance is due to several factors, including the formation of a mesoporous nanostructure with abundant active sites and the favorable effects of the Ru species. This work provides guidance toward designing and fabricating effective Pt-based electrocatalysts for DMFC applications.

Titanium Nanotubes as an Effective Electrocatalyst Support for Hydrogen Evolution Reaction

Developing proper support for hydrogen evolution reaction (HER) electrocatalysts is important for enhancing the HER efficiency and reducing the cost of green hydrogen production. TiO2-based-catalyst support has attracted considerable attention due to its commercial availability, high stability, low cost, and its unique electronic and ionic properties [1]. TiO2 is commonly utilized in various applications involving, photocatalysis, solar cells, and photoelectrochemical water splitting [2]. The ease of the synthesis of TiO2 with different morphologies and crystal structures makes it promising support to replace carbon in electrochemical applications [3]. Recently, anatase TiO2 nanoparticles decorated with PtOx clusters showed benchmark activity toward hydrogen evolution from the acidic medium with an overpotential of –125 mV at –10 mA cm–2 [4]. Furthermore, Pt clusters supported on porous TiO2 nanoparticles achieved higher stability compared with that of the benchmark Pt/C catalyst due to the facile electron transfer from TiO2 to PtOx [4]. Despite the TiO2-supported Pt nanoclusters have been recently investigated, the characteristic of HER electrocatalysts loaded on highly ordered TiO2 nanotube arrays (TNTs) is still unexplored. TNTs are expected to be an optimal support architecture owing to their large internal surface area and excellent electron mobility [5, 6]. Moreover, they can be readily synthesized and have robust mechanical stability. Therefore, in our work, highly ordered TNTs on Ti substrate have been synthesized and investigated as a support for different types of HER electrocatalysts (i.e. PtOx [7], MoS2 [8], and CoOP [9]). The PtOx clusters supported on TNTs (Ti/TNTs/PtOx) showed excellent performance for HER. An overpotential of –30 mV was sufficient to deliver –10 mA cm–2 from the acidic medium. The electrocatalytic mass activity of Ti/TNTs/PtOx (i.e. 204 mA mgPt –1) is enhanced by 12 and 1.7-fold compared to those of Pt/C and titanium nanoparticles (TNPs) supported PtOx electrocatalysts, respectively. The superior activity of the Ti/TNTs/PtOx is mainly due to its large electrochemically active surface area and the excellent electron mobility in the TNTs support. The immobilizing of MoS2 on TNTs resulted in enhanced electrocatalytic HER activity. An overpotential of –200 mVRHE was ample to deliver –10 mA cm–2 from 0.5 M H2SO4 aqueous solution. A synergy between the in-situ immobilized MoS2 and TNTs is proposed to explain the enhanced HER performance. In an alkaline medium, the Ti/TNTs/CoOP electrode fabricated by incorporating CoOP spheres into the TNTs exhibited only –130 mV overpotential to deliver –10 mA cm–2. This value is superior to that of CoOP deposited on bare Ti foil (–165 mV), FTO (–185 mV), and glassy carbon (–214 mV). In general, our study revealed that the TNTs support improves the electrochemical surface area and accessibility of active sites while reducing the charge transfer resistance at the electrode/electrolyte interface. Acknowledgments T.A.K. thanks the Deanship of Research Oversight and Coordination at KFUPM for the conference attendance support.

Interface Engineering of PtZn Alloy and Nb2O5 for Promoting Ammonia Oxidation Reaction and Hydrogen Evolution Reaction.

Ammonia electrolysis is a promising technology to obtain green hydrogen with zero-carbon emission, in which ammonia oxidation reaction (AOR) and hydrogen evolution reaction (HER) occur at the anode and cathode, respectively. However, the lack of efficient catalysts hinders its practical application. Herein, PtZn alloy is combined with Nb2O5 to construct a bifunctional heterostructure catalyst (PtZn-Nb2O5/C). The optimal sample with Nb2O5 content of 7.05 wt % demonstrates the best performance with a peak current density of 304.1 mA mg-1Pt for AOR, and it is only reduced by 17.0% after 4000 cycles of durability tests. For HER, it has a low overpotential of 34 mV at -10 mA cm-2 under the alkaline condition. This can be ascribed to the interfacial interaction between the PtZn alloy and Nb2O5, which adjusts the adsorption behavior of OHad to concurrently promote AOR and HER activity. This work thus proposes a viable strategy to design an efficient bifunctional catalyst for hydrogen generation from ammonia electrolysis.

MOFs-derived TiO2 on N-doped carbon materials with high concentration of oxygen vacancies as Pt supports and co-catalysts for methanol electrooxidation

MIL-125(Ti)–NH2 was pyrolyzed in N2 and H2/Ar gas to prepare N-doped carbon materials containing TiO2 (TiO2-NC). XPS, ESR and Raman spectra analysis showed that higher concentration of oxygen vacancies were created on the surface of TiO2 in H2/Ar gas, which provided more anchor sites for the nucleation of Pt and enhanced the interaction between Pt and TiO2. Therefore, the mass activity/specific activity of Pt/(TiO2-NC)HA catalysts for methanol oxidation was 510.7 mA mg−1Pt/2.84 mA cm−2Pt, which was 3.1/1.4 times that of Pt/(TiO2-NC)N catalysts. Due to the enriched OHads on the suface of TiO2 and the strong metal-support interaction between TiO2 and Pt, Pt/(TiO2-NC)HA catalysts exhibited stronger resistance to COads poisoning than commercial JM-Pt/C catalysts, thus showing more excellent catalytic activity and stability.

Rational Regulation of the Defect Density in Platinum Nanocrystals for Highly Efficient Hydrogen Evolution Reaction.

Constructing structural defects is a promising way to enhance the catalytic activity toward the hydrogen evolution reaction (HER). However, the relationship between defect density and HER activity has rarely been discussed. In this study, a series of Pt/WOx nanocrystals are fabricated with controlled morphologies and structural defect densities using a facile one-step wet chemical method. Remarkably, compared with polygonal and star structures, the dendritic Pt/WOx (d-Pt/WOx) exhibited a richer structural defect density, including stepped surfaces and atomic defects. Notably, the d-Pt/WOx catalyst required 4 and 16 mV to reach 10 mA cm-2, and its turnover frequency (TOF) values are 11.6 and 22.8 times higher than that of Pt/C under acidic and alkaline conditions, respectively. In addition, d-Pt/WOx//IrO2 displayed a mass activity of 5158 mA mgPt -1 at 2.0 V in proton exchange membrane water electrolyzers (PEMWEs), which is significantly higher than that of the commercial Pt/C//IrO2 system. Further mechanistic studies suggested that the d-Pt/WOx exhibited reduced number of antibonding bands and the lowest dz2-band center, contributing to hydrogen adsorption and release in acidic solution. The highest dz2-band center of d-Pt/WOx facilitated the adsorption of hydrogen from water molecules and water dissociation in alkaline medium. This work emphasizes the key role of the defect density in improving the HER activity of electrocatalysts.

Sheet-Isolated MoS2 Used for Dispersing Pt Nanoparticles and its Application in Methanol Fuel Cells.

It is highly challenging to activate the basal plane and minimize the π-π stacking of MoS2 sheets, thus enhancing its catalytic performance. Here, we display an approach for making well-dispersed MoS2 . By using the N-doped multi-walled carbon nanotubes (NMWCNTs) as an isolation unit, the aggregation of MoS2 sheets was effectively reduced, favoring the dispersion of Pt nanoparticles (noted as Pt/NMWCNTs-isolated-MoS2 ). Excellent bifunctional catalytic performance for methanol oxidation and oxygen reduction reaction (MOR/ORR) were demonstrated by the produced Pt/NMWCNTs-isolated-MoS2 . In comparison to Pt nanoparticles supported on MoS2 (Pt/MoS2 ), the MOR activity (2314.14 mA mgpt -1 ) and stability (317.69 mA mgpt -1 after 2 h of operation) on Pt/NMWCNTs-isolatedMoS2 were 24 and 232 times higher, respectively. As for ORR, Pt/NMWCNTs-isolated-MoS2 holds large half-wave potential (0.88 V) and high stability (92.71 % after 22 h of operation). This work presents a tactic for activating the basal planes and reducing the π-π stacking of 2D materials to satisfy their applications in electrocatalysis. In addition, the proposed sheet-isolation method can be used for fabricating other 2D materials to promote the dispersion of nanoparticles, which assist its application in other fields of energy as well as the environment.

Defect‐Induced Electron Redistribution between Pt‐N3S1 Single Atomic Sites and Pt Clusters for Synergistic Electrocatalytic Hydrogen Production with Ultra‐High Mass Activity

AbstractA N, S co‐doped carbon with abundant vacancy defects (NSC) anchored Pt single atoms (SAs) and nanoclusters (NCs) derived from coal pitch by a self‐assembly‐pyrolysis strategy is reported and a defect‐induced electron redistribution effect based on Pt SAs‐Pt NCs/NSC catalyst is proposed for electrocatalytic hydrogen evolution reaction (HER). The optimized catalyst featuring Pt‐N3S1 SAs and Pt NCs dual active sites exhibit excellent HER activity with an overpotential of 192 mV at a current density of 400 mA cm−2, a turnover frequency of 30.1 s−1 at an overpotential of 150 mV, which the mass activity is 13716 mA mgPt−1, 7.4 times higher than that of 20% Pt/C catalyst. In situ Raman revealsa direct correlation between the defect structure of the catalyst and hydrogen adsorption during the reaction process. Density functional theory calculation shows the defect‐induced electron redistribution between Pt‐N3S1 SAs and Pt NCs. The electrons are transferred from Pt NCs to Pt SAs, which increases the number of electrons on the surface of Pt SAs and enhances the adsorption ability of H+. Meanwhile, the dissociation ability of H* on the Pt NCs is promoted, thus synergistically promoting the HER process.

Highly Durable PtNi Alloy on Sb-Doped SnO2 for Oxygen Reduction Reaction with Strong Metal-Support Interaction.

Carbon-supported Pt is currently used as catalyst for oxygen reduction reaction (ORR) in fuel cells but is handicapped by carbon corrosion at high potential. Herein, a stable PtNi/SnO2 interface structure has been designed and achieved by a two-step solvothermal method. The robust and conductive Sb-doped SnO2 supports provide sufficient surfaces to confine PtNi alloy. Moreover, PtNi/Sb0.11 SnO2 presents a more strongly coupled Pt-SnO2 interface with lattice overlap of Pt (111) and SnO2 (110), together with enhanced electron transfer from SnO2 to Pt. Therefore, PtNi/Sb0.11 SnO2 exhibits a high catalytic activity for ORR with a half-wave potential of 0.860 V versus reversible hydrogen electrode (RHE) and a mass activity of 166.2 mA mgPt -1 @0.9 V in 0.1 M HClO4 electrolyte. Importantly, accelerated degradation testing (ADT) further identify the inhibition of support corrosion and agglomeration of Pt-based active nanoparticles in PtNi/Sb0.11 SnO2 . This work highlights the significant importance of modulating metal-support interactions for improving the catalytic activity and durability of electrocatalysts.

Synthesis of PtRe electrocatalysts supported on mesoporous carbon for the ethanol oxidation reaction

Mesoporous carbon was synthesized to be employed as support in PtRe anodic electrocatalysts. The catalysts were prepared by the polyol method with the following Re loadings: 1, 3, 5, and 10 wt.%. The N2 adsorption-desorption isotherms, thermogravimetric measurements, temperature programmed desorption and temperature programmed reduction of the support were performed and the catalysts were structurally characterized by temperature programmed reduction, H2 chemisorption, X-ray diffraction, X-ray photoelectron spectroscopy, benzene hydrogenation reaction, and transmission electron microscopy. Furthermore, the electrochemical characterization of the catalysts was carried out by cyclic voltammetry, chronoamperometry, and CO stripping techniques. The addition of Re leads to a decrease in the CO oxidation onset potential value. The PtRe(3)/MC catalyst exhibited the best electrocatalytic activity, showing an electrochemical active surface area value of 82.5 m2 gPt−1. Moreover, the potential and anodic current values for ethanol oxidation reaction were 889 mV vs Ag/AgCl and 648 mA mgPt−1, respectively. This result is consistent with electronic effects and the smallest particle size found for this catalyst.

Highly Utilized Active Sites on Pt@Cu/C for Ethanol Electrocatalytic Oxidation in Alkali Metal Hydroxide Solutions

AbstractUsing ethanol electrocatalytic oxidation reaction (EOR) with a lower reaction potential to replace oxygen evolution reaction (OER) and integrating hydrogen evolution reaction (HER) have a promising development prospect for more energy‐saving electrolytic hydrogen production. However, the main challenges of EOR are insufficient catalytic activity, high overpotential, and slow kinetics. Active sites on the electrocatalysts surface are occupied by alkali metal ion hydrate clusters by noncovalent interactions, which is considered to be one of the major causes of these challenges. To reduce the effect of the noncovalent interactions on the catalytic activity of the electrocatalyst, copper is chosen and doped in the form of a single atom in the electrocatalyst (Pt@Cu/C) to increase the electrocatalyst conductivity and make the anode contain more positive charge in this study. Then, alkali metal ion hydrate clusters are difficult to adsorb at the active site of Pt@Cu/C. The EOR electrocatalytic activity of Pt@Cu/C is up to 8184 mA mgPt−1, which is ≈4.8 times as high as that of Pt/C. The two‐electrode hydrogen production device using Pt@Cu/C as anode for coupled EOR&HER requires a smaller voltage of 0.60 V to reach 10 mA cm−2compared with that of Pt/C (0.76 V).

Facile synthesis of RuCoOx/N-CNT@PEDOT-SH/Pt for high catalytic performance of the methanol electro-oxidation

The exploration of direct methanol fuel cell (DMFC) catalysts has always been a great challenge. We present a facile method to prepare RuCoOx/N-CNT, composited with PEDOT-SH and supported Pt nanoparticles (Pt NPs) as catalyst for methanol oxidation reaction (MOR). Bimetallic oxide carbon nanotubes (RuCoOx/N-CNT) serve as a carrier and a cocatalyst, especially the introduction of RuOx into CoOx can also generate a large number of oxygen vacancies, which can be used as highly active centers as reactants to provide adsorption (or coordination) sites, facilitating electron transfer between reactants and improving the hydrophilicity of catalysts, thereby promoting redox reaction kinetics. A series of structural characterizations show that alloying and charge redistribution exist in RuCoOx/[email protected]/Pt, and oxygen vacancies can effectively change the electronic structure and improve the exposure of active sites density, thereby enhancing MOR activity. Performance tests such as CV、i-t、stability test show that the electrocatalytic activity of RuCoOx/[email protected]/Pt (2003.3 mA mg-1Pt) is far superior to that of RuCoOx/N-CNT/Pt (1324.8 mA mg-1Pt) and commercial Pt/C (279.6 mA mg-1Pt) catalysts. This strategy can provide a scheme for high-performance, low-cost anode catalyst design in MOR.