Interface-Rich Three-Dimensional Au-Doped PtBi Intermetallics as Highly Effective Anode Catalysts for Application in Alkaline Ethylene Glycol Fuel Cells

The preparation of metal electrocatalysts with excellent comprehensive properties for application in alcohol fuel cells is an urgent issue. This study reports a novel 3D Au-doped PtBi intermetallic phase woven by sub-7 nm building blocks. The high-efficiency “active auxiliary” Au advances the activity and in situ anti-CO poisoning upon ethylene glycol electrooxidation on 3D PtBiAu, along with high C C bond cleavage and attainment of a ten-electron complete electrooxidation via a CO-free pathway. The interface-rich 3D structure with “nanocontainer” function, electronic effect, and dual functional sites of “Pt–Au” or “Pt–Bi” enable the 3D PtBiAu to outperform industrial Pt black and 3D PtBi intermetallics significantly. The mass activity on the 3D Pt_53.1Bi_43.4Au_3.5 intermetallics boosts to 28.72 A mg_Pt⁻¹, higher than that reported in a previous study. The 3D Pt_53.1Bi_43.4Au_3.5 exhibits superior performance to industrial Pt/C in direct ethylene glycol fuel cells (DEGFCs). The peak power density of 3D Pt_53.1Bi_43.4Au_3.5 is 145/92 mW cm⁻² in O₂/air (80 °C). Importantly, the cell voltage shows a negligible decay in both O₂ and air during the 20 h durability testing. This study results in the development of novel 3D PtBiAu intermetallics as high-performance anode electrocatalysts for application in DEGFCs.     

Single Platinum Atoms Immobilized on Monolayer Tungsten Trioxide Nanosheets as an Efficient Electrocatalyst for Hydrogen Evolution Reaction

Monolayer WO₃·H₂O (ML-WO₃·H₂O) nanosheets are synthesized via a space-confined strategy, and then a single-atom catalyst (SAC) is constructed by individually immobilizing Pt single atoms (Pt-SA) on monolayer WO₃ (ML-WO₃). The Pt-SA/ML-WO₃ retains the monolayer structure of ML-WO₃·H₂O, with a quite high monolayer ratio up to ≈ 93%, and possesses rich defects (O and W vacancies). It exhibits excellent electrocatalytic performance, with a small overpotential (η) of − 22 mV to drive − 10 mA cm⁻² current, a low Tafel slope of ≈ 27 mV dec⁻¹, an ultrahigh turnover frequency of ≈ 87 H₂ s⁻¹ site⁻¹ at η  =   − 50 mV, and long-term stability. Of particular note, it exhibits an ultrahigh mass activity of ≈ 87 A mg_Pt⁻¹ at η  =   − 50 mV, which is ≈ 160 times greater than that of the state-of-the-art commercial catalyst, 20 wt% Pt/C ( ≈ 0.54 A mg_Pt⁻¹). Experimental and DFT analyses reveal that its excellent performance arises from the strong synergetic effect between the single Pt atoms and the support. This work provides an effective route for large-scale fabrication of ML-WO₃ nanosheets, demonstrates ML-WO₃ is an excellent support for SACs, and also reveals the great potential of SACs in reducing the amount of noble metals used in catalysts.     

Coupling Methanol Oxidation with Hydrogen Evolution on Bifunctional Co-Doped Rh Electrocatalyst for Efficient Hydrogen Generation

Efficient hydrogen production from electrochemical overall water splitting requires high-performance electrocatalysts for hydrogen evolution reaction (HER) and a fast oxidation reaction to replace sluggish oxygen evolution reaction. Herein, Co-doped Rh nanoparticles are thus grown on carbon black using Co nanosheets as the bridge. These nanoparticles with a size of ≈1.94 nm exhibit the overpotential of as low as 2 mV at 10 mA cm⁻² for the HER, and a mass activity of as high as 889 mA mg⁻¹ for the methanol oxidation reaction (MOR) in alkaline media. As confirmed by density functional theory simulations, such excellent activity originates from Co-doping, which reduces reaction energy barriers for both the rate-determining step of a Volmer process during the HER and the conversion of *CO to COOH* during the MOR (namely the enhanced adsorption of H₂O and COOH*). Coupling boosted HER on the cathode with accelerated MOR on the anode, efficient H₂ generation is achieved. This two-electrode cell only requires a cell voltage of 1.545 V at 10 mA cm⁻² with impressive long-life cycling stability. Such performance even outperforms that of commercial Pt/C || IrO₂ cell. This study offers a new strategy to achieve efficient HER from overall water splitting.     

The Edge Effects Boosting Hydrogen Evolution Performance of Platinum/Transition Bimetallic Phosphide Hybrid Electrocatalysts

Platinum (Pt) is regarded as a promising electrocatalyst for hydrogen evolution reaction (HER). However, its application in an alkaline medium is limited by the activation energy of water dissociation, diffusion of H⁺, and desorption of H*. Moreover, the formation of effective structures with a low Pt usage amount is still a challenge. Herein, guided by the simulation discovery that the edge effect can boost local electric field (LEF) of the electrocatalysts for faster proton diffusion, platinum nanocrystals on the edge of transition metal phosphide nanosheets are fabricated. The unique heterostructure with ultralow Pt amount delivered an outstanding HER performance in an alkaline medium with a small overpotential of 44.5 mV and excellent stability for 80 h at the current density of −10 mA cm⁻². The mass activity of as-prepared electrocatalyst is 2.77 A mg⁻¹_Pt, which is 15 times higher than that of commercial Pt/C electrocatalysts (0.18 A mg⁻¹_Pt). The density function theory calculation revealed the efficient water dissociation, fast adsorption, and desorption of protons with hybrid structure. The study provides an innovative strategy to design unique nanostructures for boosting HER performances via achieving both synergistic effects from hybrid components and enhanced LEF from the structural edge effect.     

Local Oxidation Induced Amorphization of 1.5-nm-Thick Pt–Ru Nanowires Enables Superactive and CO-Tolerant Hydrogen Oxidation in Alkaline Media

Low-dimensional amorphous metallic nanomaterials provide great possibility for creating high-performance electrocatalysts owing to their conspicuous reacting merits derived from the flexible coordination structures, but remain extremely challenging in synthesis. Herein, this work reports a facile synthesis of carbon-loaded amorphous 1.5-nm-thick Pt–Ru nanowires (NWs) through a local oxidation induced amorphization process. During annealing premade crystalline Pt–Ru NWs/C in air, a local-oxidation of the oxyphilic Ru generates abundant random Ru–O bonds and disturbs the order bimetallic lattices. The as-prepared amorphous Pt₅₃Ru₄₇ (a-Pt₅₃Ru₄₇) NWs/C exhibits an extremely high activity (13.7 A mg⁻¹ at 25 mV overpotential) and an excellent CO-tolerance for alkaline hydrogen oxidation reaction (HOR) electrocatalysis, drastically outperforming the crystalline counterpart and commercial benchmarks. Mechanism studies indicate the Pt–Ru bimetallic effects as well as the rich disordered “Pt–Ru–O” and/or “Pt–O–Ru” atomic heterojunctions can weaken the *H binding energy and inversely strengthen the *OH adsorption, thus promoting the alkaline HOR kinetics. More uniquely, the small interatomic spaces derived from the disordered bond nets present a H₂/*H-selected permeability, which spatially obstruct the relatively larger CO molecules to poison the internal catalytic sites during HOR. The CO-shielded internal catalytic sites and the enriched surface *OH jointly upgrade the CO-tolerance of the a-Pt₅₃Ru₄₇ NWs/C catalysts.     

PtCo@NCs with Short Heteroatom Active Site Distance for Enhanced Catalytic Properties

The crucial issue for fuel cells is to improve the activity and durability of Pt‐based catalysts. Herein, based on the short distance enhancement effects, a novel PtCo@NC catalyst with remarkably enhanced electrocatalytic properties for methanol oxidation reaction (MOR) in acidic electrolytes is developed by shortening the Pt–Co active site distance. In brief, a series of PtCo@NC catalysts with different Pt–Co biatomic arrangement are precisely synthesized by an in situ reduction‐fusion method, achieving Pt–Co structural evolution from a Pt/Co individual monometallic islet (A‐700 °C) to PtCo heterodimer (A‐800 °C) and then a PtCo alloy (A‐900 °C) embedded on nitrogen‐doped carbon matrixes. Compared with the Pt/Co monometallic islet and heterodimer, the PtCo@NC (A‐900 °C) with the shortest Pt–Co active site distance exhibits the highest mass activity of 2.30 A mg_Pt^?1, which is 12.23 times higher than that of commercial Pt/C and exceeds almost all the reported MOR catalysts in acidic electrolytes. Both experiments and density functional theory calculations reveal that the remarkably improved activity stems from the modification of electron distribution around Pt/Co metal centers, thus promoting the rate‐determining methanol dehydrogenation step and CO oxidative removal processes, which are dependent on the distance between bimetallic active sites.     

Replicating the Defect Structures on Ultrathin Rh Nanowires with Pt to Achieve Superior Electrocatalytic Activity toward Ethanol Oxidation

Metal nanostructures with an ultrathin Pt skin and abundant surface defects are attractive for electrocatalytic applications owing to the increased utilization efficiency of Pt atoms and the presence of highly reactive sites. This paper reports a conformal, layer‐by‐layer deposition of Pt atoms on defective Rh nanowires for the faithful replication of surface defects (i.e., grain boundaries) on the Rh nanowires. The thickness of the Pt shell can be controlled from one monolayer up to 5.3 atomic layers. This series of Rh@Pt_nL (n = 1–5.3) core–sheath nanowires show greatly enhanced activity and durability in catalyzing the ethanol oxidation reaction in an acidic medium. Among others, the Rh @ Pt_3.5L nanowires show the greatest mass activity (809 mA mg^?1_Pt) and specific activity (1.18 mA cm^?2) after loaded on carbon support, which are 3.7 and 3.4 times those of the commercial Pt/C, respectively. In situ Fourier transform infrared spectroscopy studies indicate an enhanced interaction between the outermost Pt layer and the Rh nanowire can promote C? C bond cleavage for complete oxidation of ethanol to CO₂ while depress the dehydrogenation of ethanol to acetic acid. As the Pt shell thickness is increased, the selectivity for the CO₂ pathway decreases while that for acetic acid is increased.     

Flexible Solid-State Direct Ethanol Fuel Cell Catalyzed by Nanoporous High-Entropy Al-Pd-Ni-Cu-Mo Anode and Spinel (AlMnCo)3O4 Cathode

As in many other electrochemical energy-converting systems, the flexible direct ethanol fuel cells rely heavily on high-performance catalysts with low noble metal contents and high tolerance to poisoning. In this work, a generic dealloying procedure to synthesize nanoporous multicomponent anodic and cathodic catalysts for the high-performance ethanol fuel cells is reported. On the anode side, the nanoporous AlPdNiCuMo high-entropy alloy exhibits an electrochemically active surface area of 88.53 m² g⁻¹_Pd and a mass activity of 2.67 A mg⁻¹_Pd for the ethanol oxidation reaction. On the cathode side, the dealloyed spinel (AlMnCo)₃O₄ nanosheets with no noble metals demonstrate a comparable catalytic performance as the standard Pt/C for the oxygen reduction reaction, and tolerance to high concentrations of ethanol. Equipped with such anodic and cathodic catalysts, the flexible solid-state ethanol fuel cell is able to deliver an ultra-high energy density of 13.63 mWh cm⁻² with only 3 mL ethanol, which is outstanding compared with other similar solid-state energy devices. Moreover, the solid-state ethanol fuel cell is highly flexible, durable and exhibits an inject-and-run function.     

Pt–Cu Interaction Induced Construction of Single Pt Sites for Synchronous Electron Capture and Transfer in Photocatalysis

Single-atom photocatalysts have shown their fascinating strengths in enhancing charge transfer dynamics; however, rationally designing coordination sites by metal doping to stabilize isolated atoms is still challenging. Here, a one-unit-cell ZnIn₂S₄ (ZIS) nanosheet with abundant Cu dopants serving as the suitable support to achieve a single atom Pt catalyst (Pt₁/Cu–ZIS) is reported, and hence the metal single atom–metal dopant interaction at an atomic level is disclosed. Experimental results and density functional theory calculations highlight the unique stabilizing effect (Pt–Cu interaction) of single Pt atoms in Cu-doped ZIS, while apparent Pt clusters are observed in pristine ZIS. Specifically, Pt–Cu interaction provides an extra coordination site except three S sites on the surface, which induces a higher diffusion barrier and makes the single atom more stable on the surface. Apart from stabilizing Pt single atoms, Pt–Cu interaction also serves as the efficient channel to transfer electrons from Cu trap states to Pt active sites, thereby enhancing the charge separation and transfer efficiency. Remarkably, the Pt₁/Cu–ZIS exhibits a superb activity, giving a photocatalytic hydrogen evolution rate of 5.02 mmol g⁻¹ h⁻¹, nearly 49 times higher than that of pristine ZIS.     

Ultrahigh Mass Activity for the Hydrogen Evolution Reaction by Anchoring Platinum Single Atoms on Active {100} Facets of TiC via Cation Defect Engineering

Improving the platinum (Pt) mass activity for low-cost electrochemical hydrogen evolution is an important and arduous task. Here, a selective etching-reducing fluidized bed reactor technique is reported to create Ti vacancies and firmly anchor single Pt atoms on the active {100} facets of titanium carbide (TiC) to increase the Pt utilization efficiency and improve catalytic activity significantly by a synergistic effect between Ti vacancies and Pt atoms. The generated Ti vacancies are negatively charged and stabilize Pt atoms by forming covalent Pt C bonds, showing excellent long-term durability. Pt single atoms (ultralow load of 1.2 µg cm⁻²) on the defective TiC {100} show remarkable activity (24.9 mV at 10 mA cm⁻²) and a mass activity (49.69 A mg⁻¹) ≈190 times that of the state-of-the-art Pt C catalyst and nearly double the previously reported best values. The developed cation defect engineering exhibits excellent potential for fabricating next-generation advanced single-atom catalysts for large-scale hydrogen evolution at a low cost.     

Ultrasmall Pd‐Cu‐Pt Trimetallic Twin Icosahedrons Boost the Electrocatalytic Performance of Glycerol Oxidation at the Operating Temperature of Fuel Cells

Recently, in order to improve the energy conversion efficiency of direct polyol fuel cells, the engineering of effective Pd‐ and/or Pt‐based electrocatalysts to rupture C? C bonds has received increasing attention. Here, an example is shown to synthesize highly uniform sub‐10 nm Pd‐Cu‐Pt twin icosahedrons by controlling the nucleation phase. Because of the synergies of the electronic effect, synergistic effect, geometric effect, and abundant surface active sites originating from the formation of near surface alloy and special icosahedral shape, the Pd‐Cu‐Pt twin icosahedrons exhibit excellent electrocatalytic performance in glycerol electrocatalysis at the operating temperature of direct alcohol fuel cells (70 °C) in KOH electrolyte. The Pd_50.2Cu_38.4Pt_11.4 icosahedrons show mass activities of 9.7 A mg^?1_Pd+Pt and 13.7 A mg^?1_Pd. Furthermore, the Pd_50.2Cu_38.4Pt_11.4 icosahedrons demonstrate long‐term durability in current–time test for 36 000 s and high in situ anti‐CO poisoning performance. In addition, the introduction of CO can enhance electro‐oxidation endurance on Pd_50.2Cu_38.4Pt_11.4 icosahedrons, and the peak mass activity can reach to 14.4 A mg^?1_Pd+Pt. The in situ Fourier transform infrared spectroscopy spectra indicate that the Pd_50.2Cu_38.4Pt_11.4 icosahedrons possess a high capacity to break C? C bonds and may efficiently convert glycerol into CO₂, thus improving the utilization efficiency of energy‐containing molecule glycerol.     

A Highly Efficient pH-Universal HOR Catalyst with Engineered Electronic Structures of Single Pt Sites by Isolated Co Atoms

Developing a high-efficiency, stable, and CO-toxicant-resistant low-cost hydrogen oxidation reaction (HOR) electrocatalyst is challenging but is vital for practical proton/anion exchange membrane fuel cells. Herein, an efficient pH-universal HOR catalyst Pt₁@Co₁CN is fabricated, in which the electronic structure of single Pt sites is modulated by isolated Co atoms pre-anchored on nitrogen-doped carbon. Pt₁@Co₁CN exhibits superior HOR activity and durability under pH-universal media than Pt₁@CN (anchored single Pt atoms on nitrogen-doped carbon) and commercial PtRu/C and Pt/C. More importantly, Pt₁@Co₁CN possesses much better CO anti-poisoning ability than Pt₁@CN and commercial PtRu/C and Pt/C. It is speculated that the superior pH-universal HOR performance can be attributed to the inter-regulation of adjacent Co and Pt sites, leading to the downshift of anti-bonding state and consequently strengthening the *H adsorption, which promotes the kinetics of HOR.     

Anti-Corrosive SnS2/SnO2 Heterostructured Support for Pt Nanoparticles Enables Remarkable Oxygen Reduction Catalysis via Interfacial Enhancement

The stability of Pt-based catalysts for oxygen reduction reaction (ORR) in hydrogen fuel cells is seriously handicapped by the corrosion of their carbon supports at high potentials and acidic environments. Herein, a novel SnS₂/SnO₂ hetero-structured support is reported for Pt nanoparticles (NPs) as the ORR catalyst, where Pt NPs are mainly deposited at the interfaces of SnS₂ and SnO₂ moieties. The Pt-support interactions, which can be tuned by the concentration of the heterointerfaces, can accelerate the electronic transfer and enrich the electron density of Pt with a favorable shift of the d-band center. In electrochemical measurements, the ORR mass activity (MA) of the optimal Pt-SnS₂/SnO₂ catalyst at 0.9 V versus RHE (0.40 A mg_Pt⁻¹) is four times higher than that of Pt/C. As for the stability, the electrochemical active surface area and MA of Pt-SnS₂/SnO₂ are only decreased by 18.2% and 23.7% after 50 000 potential cycles at a high potential region (1.0–1.6 V), representing the best ORR stability among the reported Pt-based catalysts. Density functional theory calculations indicate that the binding energy and migration barrier of Pt atom/cluster on the SnS₂/SnO₂ heterojunction are much higher relative to other supports, accounting for the outstanding stability of the catalyst.     

Atomically Dispersed Unsaturated Cu-N3 Sites on High-Curvature Hierarchically Porous Carbon Nanotube for Synergetic Enhanced Nitrate Electroreduction to Ammonia

Cu-based single-atom catalysts (SACs) are regarded as promising candidates for electrocatalytic reduction of nitrate to ammonia (NO₃RR) owing to the appropriate intrinsic activity and the merits of SACs. However, most reported Cu SACs are based on 4N saturated coordination and supported on planer carbon substrate, and their performances are unsatisfactory. Herein, low-coordinated Cu-N₃ SACs are designed and constructed on high-curvature hierarchically porous N-doped carbon nanotube (NCNT) via a stepwise polymerization–surface modification–electrostatic adsorption–carbonization strategy. The Cu-N₃ SACs/NCNT exhibits outstanding NO₃RR performance with maximal Faradaic efficiency of 89.64% and NH₃ yield rate of up to 30.09 mg mg_cat⁻¹ h⁻¹ (70.8 mol g_Cu⁻¹ h⁻¹), superior to most reported SACs and Cu-based catalysts. The results integrated from potassium thiocyanide poisoning experiments, online differential electrochemical mass spectrometry, in situ Fourier transform infrared spectroscopy, and density functional theory calculations demonstrate: 1) unsaturated Cu is active site; 2) Cu-N₃ SACs/NCNT possesses NO*-HNO*-H₂NO*-H₂NOH* pathway; 3) low-coordinated Cu-N₃ sites and high-curvature carbon support synergetic promote reaction dynamics and reduce rate-determining step barrier. This study inspires a synergetic enhancement catalysis strategy of creating unsaturated coordination environment and regulating support structure.     

Development and Simulation of Sulfur‐doped Graphene Supported Platinum with Exemplary Stability and Activity Towards Oxygen Reduction

Sulfur‐doped graphene (SG) is prepared by a thermal shock/quench anneal process and investigated as a unique Pt nanoparticle support (Pt/SG) for the oxygen reduction reaction (ORR). Particularly, SG is found to induce highly favorable catalyst‐support interactions, resulting in excellent half‐cell based ORR activity of 139 mA mg_Pt ^?1 at 0.9 V vs RHE, significant improvements over commercial Pt/C (121 mA mg_Pt ^?1) and Pt‐graphene (Pt/G, 101 mA mg_Pt ^?1). Pt/SG also demonstrates unprecedented stability, maintaining 87% of its electrochemically active surface area following accelerated degradation testing. Furthermore, a majority of ORR activity is maintained, providing 108 mA mg_Pt ^?1, a remarkable 171% improvement over Pt/C (39.8 mA mg_Pt ^?1) and an 89% improvement over Pt/G (57.0 mA mg_Pt ^?1). Computational simulations highlight that the interactions between Pt and graphene are enhanced significantly by sulfur doping, leading to a tethering effect that can explain the outstanding electrochemical stability. Furthermore, sulfur dopants result in a downshift of the platinum d‐band center, explaining the excellent ORR activity and rendering SG as a new and highly promising class of catalyst supports for electrochemical energy technologies such as fuel cells.     

Metal–Organic Framework-Derived N-Doped Carbon with Controllable Mesopore Sizes for Low-Pt Fuel Cells

Mesoporous structure of carbon materials plays an important role in electrocatalyst design. Constructing carbon supports with tunable mesopores has long been a challenge. Herein, the elaborate regulation of mesopores in N-doped carbon materials is reported by pyrolyzing energetic metal-triazolate (MET) frameworks with different particle sizes and at different ramp rates. Higher thermal transfer rates brought about by smaller particle size and higher ramp rate lead to more violent decomposition with a large number of gases producing, which in turn result in larger mesopores in the derivatives. Consequently, a series of N-doped carbon materials with controllable mesopores are obtained. As a proof-of-concept, ultrafine Pt nanoparticles are enveloped inside these mesopores to acquire high-performance electrocatalysts for oxygen reduction reaction. The optimized catalyst achieves high mass activity of 1.52 A mg_Pt⁻¹ at 0.9 V_iR-free and peak power density of 0.8 W cm⁻² (H₂-Air) with an ultralow Pt loading of 0.05 mg_Pt cm⁻² at cathode in fuel cells, highlighting the great advantages of MET-derived carbon materials with controllable mesopores in the preparation of advanced electrocatalysts.     

Atomic Pt-N4 Sites in Porous N-Doped Nanocarbons for Enhanced On-Site Chlorination Coupled with H2 Evolution in Acidic Water

Acidic water electrolysis (AWE) has the potential to revolutionize green H₂ generation with flexible partial load range, high gas purity, and rapid system response. However, the extensive usage of noble Ru/Ir metals and sluggish oxygen evolution reaction (OER) with inexpensive O₂ products pose significant challenges in anodes. Herein, it is demonstrated that ultralow Pt single atoms in highly porous N-doped carbons (Pt₁/p-NC@CNTs) can effectively catalyze chlorine evolution reaction (CER) for on-site chlorination to replace OER in AWE, with 200 mV potential saving at 10 mA cm⁻². As a result, various organic halide motifs of pharmaceutical molecules by chlorinating anisole, ketones, and olefins can be realized, along with H₂ coproduction. Combined physicochemical characterizations including synchrotron X-ray absorption spectroscopy, finite element methodsimulations, and theory calculations indicate that atomic Pt-N₄ active sites balance the adsorption/desorption of Cl intermediates (Volmer step) and the plentiful porosity of Pt₁/p-NC@CNTs with high specific surface area of 313 m² g⁻¹ enriches Cl⁻ around active sites (Heyrovský step), collectively promoting the rate-limiting Volmer–Heyrovský pathway for improved CER.     

Harnessing the Extracellular Electron Transfer Capability of Geobacter sulfurreducens for Ambient Synthesis of Stable Bifunctional Single-Atom Electrocatalyst for Water Splitting

Single-atom metal (SA-M) catalysts with high dispersion of active metal sites allow maximum atomic utilization. Conventional synthesis of SA-M catalysts involves high-temperature treatments, leading to low yield with a random distribution of atoms. Herein, a nature-based facile method to synthesize SA-M catalysts (M = Fe, Ir, Pt, Ru, Cu, or Pd) in a single step at ambient temperature, using the extracellular electron transfer capability of Geobacter sulfurreducens (GS), is presented. Interestingly, the SA-M is coordinated to three nitrogen atoms adopting an MN₃ on the surface of GS. Dry samples of SA-Ir@GS without further heat treatment show exceptionally high activity for oxygen evolution reaction when compared to benchmark IrO₂ catalyst and comparable hydrogen evolution reaction activity to commercial 10 wt% Pt/C. The SA-Ir@GS exhibits the best water-splitting performance compared to other SA-M@GS, showing a low applied potential of 1.65 V to achieve 10 mA cm⁻² in 1.0 M KOH with cycling over 5 h. The density functional calculations reveal that the large adsorption energy of H₂O and moderate adsorption energies of reactants and reaction intermediates for SA-Ir@GS favorably improve its activity. This synthesis method at room temperature provides a versatile platform for the preparation of SA-M catalysts for various applications by merely altering the metal precursors.     

Trimetallic Porous PtIrBi Nanoplates with Robust CO Tolerance for Enhanced Formic Acid Oxidation Catalysis

Spreading the formic acid (HCOOH) fuel cells demands a better anode electrocatalyst for the oxidation of formic acid. The catalytic efficiency of platinum (Pt)– the only choice of practicability, is mainly limited by its intrinsic affinity to CO, thus desiring a proper release. Herein, theoretical calculations are first leveraged to find that the introduction of iridium (Ir) can facilitate HCOOH oxidation with robust CO tolerance through a dehydrogenation pathway. Then, this strategy experimentally by designing a new trimetallic catalyst of 2D porous PtIrBi nanoplates (p-PtIrBi NPs) is implemented. The optimized p-PtIrBi NPs/C exhibits a very high mass activity of 8.2 A mg⁻¹_pt and a high retention rate of 55.9% after the durability test, which is among the best formic acid oxidation catalysts reported to date, much higher than those of PtIrBi NPs/C, PtBi NPs/C, and Pt/C. The CO-stripping and in situ Fourier transform infrared (FTIR) experiments collectively evidence that two types of due site, i.e., “Pt-Bi” and “Ir-Bi”, endow the catalyst with suppressed CO-poisoning property to achieve super-high activity and stability for formic acid oxidation reaction.     

Fine AgPd Nanoalloys Achieving Size and Ensemble Synergy for High-Efficiency CO2 to CO Electroreduction

Alloying the active metal with a second metal is an effective way to tailor the adsorption of reaction intermediates through an ensemble effect. Herein, based on theoretical calculations validating that the ensemble sites composed of Ag and Pd atoms could reduce the energy gap for *COOH and *CO intermediates generated during electrocatalytic CO₂ reduction reaction (eCO₂RR) by either weakening the CO adsorption or enhancing the COOH adsorption, a strategy to produce AgPd alloy nanoparticles with fine sizes for synergizing the ensemble effect and size leverage toward high CO faradaic efficiency in eCO₂RR is reported. In particular, the AgPd alloy nanoparticles at an optimized Ag/Pd atomic ratio of 35/65 affords a maximum CO faradaic efficiency of 98.9% and a CO partial current density of 5.1 mA cm⁻² at the potential of −0.8 V (vs RHE) with satisfactory durability of up to 25 h, outperforming those of most Pd-based electrocatalysts recently reported and demonstrating great potential for further application in producing CO via eCO₂RR at ambient conditions.