Pd Precursor Research Articles

W18O49 sensitized with Pd nanoparticles for ultrasensitive ppb-level formaldehyde detection

The rapid detection of ppb-level formaldehyde is desirable but challenging for both air quality monitoring and health. Herein, we adopt the ultrasonic-solvothermal method to co-assemble W and Pd precursors to developing a direct and controllable flower-like W18O49 synthesis method, in which evenly dispersed Pd NPs are tightly fixed on the surface of the nanostructure for efficient formaldehyde detection. The sensitization of Pd NPs increases the oxygen vacancies and provides plenty of accessible sites for gas molecules. Meanwhile, the synergistic effect of Pd NPs and flower-like W18O49 interface promotes electron transfer. Thus, the enhanced gas sensing performance of the Pd-sensitized W18O49 could be attributed to chemical and electronic sensitization. The Pd-sensitized W18O49 sensor exhibits extremely low actual detection concentration (50 ppb), ultrasensitive (2.96/50 ppb), ultrafast response (1 sec), excellent reversibility, and good selectivity. DFT theoretical calculations systematically validate the gas sensing mechanism of Pd-sensitized W18O49 for formaldehyde. This work provides new insights into the design strategy of Pd-sensitized W18O49 nanomaterials for high-performance quantitative detection of formaldehyde gas sensors.

Controllable synthesis of oxygenated carbon supported palladium nanodendrites for highly efficient nitroaromatics reduction

Palladium nanodendrites supported on oxygenated carbon layer (Pd/ O-carbon) have been prepared herein through modulating the mass ratio of Pd (II) precursor and carbon dots derived from sucrose without additional reducing agent. Characterizations of FT-IR, XPS spectra and TEM graphs reveal that oxygen-bearing groups on carbon dots play important role in reducing Pd(II) into Pd(0), controlling nanoparticle growth and stabilizing Pd nanodendrites. The as-prepared Pd/ O-carbon presents size-dependent activity on catalytic p-nitrophenol (4-NP) reduction using NaBH4 as hydrogen donor. The reaction rate constant of 4-NP on Pd/ O-carbon with Pd particle size of 4–7 nm almost triples that on catalyst with Pd nanoparticles of 6–10 nm. Pd / O-carbon can be reused for 10 times without obvious decreased activity, showing a long-term chemical stability in 4-NP reduction reaction. In addition, Pd / O-carbon achieves ∼100% selectivity on nitrobenzene conversion and > 95% selectivity for the hydrogenation of substituted nitrobenzene compounds with methyl-, chloro- and amino- groups to corresponding aniline through tandem reaction with NH3BH3 as hydrogen donor in methanol/ water solvent (volume ratio of 1:3).

Strategies for palladium nanoparticles formation on halloysite nanotubes and their performance in acetylene semi‑hydrogenation

Pd nanoparticles are widely applied in catalysis. In this work, the deposition of Pd nanoparticles onto halloysite (Hal) nanotubes from different Pd precursors and solvents has been investigated. The prepared Pd/Hal catalysts have been characterized by low-temperature N2 adsorption, transmission electron microscopy, zeta potential measurement, and tested in the hydrogenation of acetylene. On calcined Hal, the largest nanoparticles are formed in acid media, and the smallest are formed in non-aqueous one. Silanization of halloysite decreases absolute values of its zeta potential significantly and drops PdNPs size twice. Catalytic tests have shown that acetylene conversion and selectivity to ethylene depend on the deposition method, and the most active catalysts were prepared from Pd acetate dissolved in acetone. The lowest activity and highest selectivity to ethylene were demonstrated by the azine-modified halloysite, that could be related to Pd poisoning with nitrogen.

Harvesting PdH Employing Pd Nano Icosahedrons via High Pressure.

Palladium hydrides (PdHx ) have important applications in hydrogen storage, catalysis, and superconductivity. Because of the unique electron subshell structure of Pd, quenching PdHx materials with more than 0.706 hydrogen stoichiometry remains challenging. Here, the 1:1 stoichiometric PdH ( is successfully synthesized using Pd nano icosahedrons as a starting material via high-pressure cold-forging at 0.2 GPa. The synthetic initial pressure is reduced by at least one order of magnitude relative to the bulk Pd precursors. Furthermore, PdH is quenched at ambient conditions after being laser heated ≈2000 K under ≈30 GPa. Corresponding ab initio calculations demonstrate that the high potential barrier of the facets (111) restricts hydrogen atoms' diffusion, preventing hydrogen atoms from combining to generate H2 . This study paves the way for the high-pressure synthesis of metal hydrides with promising potential applications.

Microstructure and activity of Pd catalysts prepared on commercial carbon support for the liquid phase decomposition of formic acid

In this work, a series of Pd catalysts supported on commercially available activated carbon (Norit ®) were prepared by employing different metal precursors (Pd(NO3)2 and Na2PdCl4) by the impregnation-reduction method at different pH. Catalysts were tested for the liquid phase decomposition of formic acid to generate hydrogen. The best results, in terms of small particle size and high catalytic activity were achieved for the Pd/C sample prepared by using Pd(NO3)2 salt impregnated at pH = 2.5, and reduced with sodium borohydride. The particle size of the best Pd/C catalyst is (4.1 ± 1.4) nm with initial TOFs of 2929 and 683 h−1 at 60 and 30 °C respectively and an apparent activation energy of 40 kJ mol−1. Samples prepared by using Na2PdCl4 precursor, consisted of particles with higher size and thus lower activity than the ones prepared with Pd(NO3)2. Regardless the Pd precursor employed, the best results in terms of particle size and activity were achieved at the point of zero charge of the support when the Pd species and the carbon surface were both neutral. The impregnation pH not only determines the particle size, but also the nature of the reducing agent does. The catalytic activity was shown to be size-dependent and it was shown that a mixture of surface Pd0 and PdII oxidation states is beneficial for the activity. When comparing with literature catalysts with similar composition, we found that our best catalyst is competitive enough and that Norit ® support could be promising for future studies on this reaction.

Effect of Pd precursors on the catalytic properties of Pd/CeO2 catalysts for CH4 and CO oxidation

Herein, Pd/CeO2 catalysts were prepared using different Pd precursors and applied to CH4 and CO oxidation. Significantly, the Pd/CeO2 catalyst prepared using palladium nitrate (Pd(2)/CeO2 (N)) was highly active toward CH4 oxidation, whereas the catalyst prepared using palladium acetate (Pd(2)/CeO2 (A)) exhibited high CO oxidation activity. The effects of the precursor on the catalytic activity and other properties were studied using various characterization techniques. The Pd(2)/CeO2 (N) catalyst contained surface PdO nanoparticles, which were active sites for CH4 oxidation. On the contrary, the Pd(2)/CeO2 (A) catalyst possessed Pd ions stabilized at CeO2 defect sites, which were not very reactive. However, the high Pd dispersion was beneficial for the CO oxidation reaction. Therefore, the Pd precursor clearly altered the Pd dispersion and state in the Pd/CeO2, which are critical for catalytic activity.

Preparation of Pd-ZIF-8 single-atom catalyst with supercritical CO2 deposition method

In recent years, single-atom catalysts (SAC) have emerged as a new frontier in the field of heterogeneous catalysis owing to their unique properties and minimized metal dosage. Herein, the Pd-ZIF-8 single-atom catalyst was successfully fabricated using ZIF-8 as support, and Pd(hfac)2 as the precursor using the supercritical CO2 deposition method. Aberration-corrected high-angle annular dark-field scanning transmission electron microscopy (AC-HAADF-STEM) images confirmed the formation of uniformly dispersed Pd atoms. Supercritical CO2 has the advantage of zero-surface tension and high diffusibility, it can carry the molecules of Pd precursor into the micropores of ZIF-8. The dissolution and diffusion of precursor were observed by a visual view cell and the mechanism of the preparation was analyzed. Finally, semi-hydrogenation of phenylacetylene to styrene was performed to evaluate the catalytic activity of the prepared Pd-ZIF-8 catalyst. The conversion rate of 80.7% and selectivity of 92.2% were obtained at 70 °C and 4 h in the semi-hydrogenation of phenylacetylene.

Intermetallic PdZn/TiO2 catalysts for methanol production from CO2 hydrogenation: The effect of ZnO loading on PdZn-ZnO sites and its influence on activity

In this work, intermetallic PdZn-ZnO catalysts supported on high surface area TiO2 were synthesized using metal-organic precursors and different Zn/Pd molar ratio (2.5, 5 and 7.5). The use of organic Pd and Zn precursors in the impregnation of TiO2 has made it possible to achieve the formation of PdO and ZnO nanoparticles that facilitate the uniform formation of small intermetallic β-PdZn particles after reduction with hydrogen at 450 °C. No significant differences in formation, crystallinity or size of intermetallic PdZn particles with varying the Zn concentration were observed. The differences were in the characteristics of the ZnO particles that lead to enhanced development of the contacts between the PdZn and ZnO particles . The best methanol yield (78.9 mmolMeOH·min−1·molPd−1) was obtained over the catalyst with highest ZnO content. This was consequence of the higher development of PdZn-ZnO interfaces, where CO2 adsorption and hydrogenation of intermediate species to methanol occurs, as well as of the higher stability of the largest ZnO particles under reaction conditions.

Synergistically Activated Pd Atom in Polymer-Stabilized Au23Pd1 Cluster.

Single Pd atom doped Au23Pd1 clusters stabilized by polyvinylpyrrolidone (Au23Pd1:PVP) were selectively synthesized by kinetically controlled coreduction of the Au and Pd precursor ions. The geometric structure of Au23Pd1:PVP was investigated by density functional theory calculation, aberration-corrected transmission electron microscopy, extended X-ray absorption fine structure analysis, Fourier transform infrared spectroscopy of adsorbed CO, and hydrogenation catalysis. These results showed that Au23Pd1:PVP takes polydisperse but the same atomic arrangements as undoped Au24:PVP while exposing all the atoms including the Pd atom on the surface. Au23Pd1:PVP exhibited a significantly higher catalytic activity than Au24:PVP for the aerobic oxidation of p-substituted benzyl alcohols. The kinetic studies showed that the rate-determining step was the hydride abstraction from the α-carbon of the alkoxides for both systems. The activation energy for hydride abstraction by Au23Pd1:PVP was lower than that by Au24:PVP, indicating that the doped Pd atom acts as the active center.

PdNP@Cyclodextrin on Cu/Al LDH-containing nanocomposites: Cage effect, crystallite size tuning and composite topology towards cross-couplings

A series of Cu/Al layered double hydroxides and Pd(0/II) composites containing native and modified cyclodextrins were prepared under different conditions of solvent (water or N,N-dimethylformamide), Pd precursors (Na2PdCl4 or Pd2dba3) and cyclodextrin/Pd ratios for the catalytic evaluation in Pd/Cu catalyzed cross-couplings aiming for the preparation of aryl thiophenes and N-arylamines. According to XPS measurements, the nanocomposites prepared in water presented a higher Pd(II)/Pd(0) ratio and subtle evidence of [PdCl4]2− intercalation by analyses of X-ray diffractograms. On the other hand, those prepared in N,N-dimethylformamide showed a higher content of Pd(0), probably dispersed on layered double hydroxides surface. SEM-FEG analyses combined with particle size distribution revealed that cyclodextrins were able to tune the size distribution, especially the β-form (15 nm in the presence of cyclodextrins). Powder X-rays diffraction data refinement using Rietveld method revealed that controlled palladium crystallite sizes of 11.53 nm and 10.22 nm were obtained in the presence of hydroxypropylated cyclodextrins (β and γ forms). Notably, the Rietveld refinement of the Pd nanocomposites revealed the presence of malachite, gibbsite, and sperniite phases in 23.05%, 23.05%, 15.23% contents. It suggests that Pd introduces a distortion in the initial LDH lattice. The catalytic activities of these nanocomposites were evaluated in Suzuki-Miyaura reaction in water/ethanol mixture, under low Pd loadings and room-temperature. Noteworthy, the nanocomposite prepared in N,N-dimethylformamide with native β-cyclodextrin showed higher catalytic activity (turnover number up to 7379) in Suzuki-Miyaura and Buchwald-Hartwig reactions for the synthesis of 2-aryl thiophenes, a component of several classes of functional organic electronic materials, and N-(4-nitrophenyl)-1,2-ethanediamine, respectively. This same nanocomposite was recycled up to three runs without loss in catalytic activity. A tentative test envisaging a one-pot borylation-Suzuki-Miyaura strategy indicated that the Miyaura borylation was conceivably affected by the coexisting malachite and spertiniite phases in the nanocomposite. However, control experiments in the presence of Cu(OH)2, Al(OH)3 and malachite indicate a lack of catalytic activity for these phases in Suzuki-Miyaura reactions. Thus, the catalytic activity is mostly attributed to the nanocomposite Cu–Al LDHs containing CDs. The enhancement in catalytic activity is suggested to occur as a result of deprotonation/adsorption of phenylboronic acid, transmetallation facilitated by a relatively high surface hydroxyl sites, improved substrate complexation by β-CDs and potential soluble Cu(II) active species from the layered matrix.

Design of γ-Alumina-Supported Phosphotungstic Acid-Palladium Bifunctional Catalyst for Catalytic Liquid-Phase Citral Hydrogenation

This study primarily addresses the development of dynamic, selective and economical metal–acid (bifunctional) catalysts for one-pot menthol production by citral hydrogenation. Specifically, various metals such as Pd, Pt, Ni, Cs and Sn were doped over alumina support. Additionally, bifunctional composite catalysts were also prepared with the impregnation of heteropoly acids and Pd precursors over alumina support. Analytical techniques (e.g., BET, PXRD, FT-IR, pyridine adsorption and amine titration methods) were applied for characterization of the most efficient and selective catalysts (e.g., Al2O3 and PTA-Cat-I). Similarly, most of the essential operational variables (e.g., loading rate of metal precursor, type of heteropoly acid, temperature, gas pressure and reaction time) were examined during this study. The experimental data shows that the bifunctional catalyst (PTA-Cat-I) produced 45% menthol at full citral substrate conversion (r = 0.038 mmoles.min−1) in liquid-phase citral hydrogenation (at optimized operating conditions: 70 °C, 0.5 MPa and 8 h). However, the heteropoly acid-supported bifunctional catalysts (e.g., PTA-Cat-I, PMA-Cat-I, SMA-Cat-I and STA-Cat-I) resulted in cracking and the dehydration of isopulegol/menthol by the generation of side products (e.g., 4-isopropyl-1-methyl, cyclohex-1-ane/ene); therefore, menthol yield was extensively diminished. On the other hand, non-acidic catalysts (e.g., Cat-I, Cat-II, Cat-III, Cat-IV and Cat-V) readily promoted hydrogenation reactions. The optimum menthol yield occurred due to the presence of strong Lewis and weak Bronsted acid sites. Mass transfer and reaction rate were substantially diminished due to acidity strength, heteropoly acid type and blockage of pores by the applied bifunctional catalysts.

Ordered Ag@Pd alloy supported on Ti4O7 by ascorbic acid-assisted galvanic replacement for efficient oxygen reduction

Core-shell catalysts have been extensively researched in enhancing the activity of oxygen reduction reaction (ORR) by modifying bimetallic electrons. However, the conventional methods for synthesizing core-shell structures are not appropriate for supported catalysts. Here, we present a strategy to support ordered Ag@Pd core-shell structures on the Ti4O7 surface by ascorbic acid-assisted galvanic replacement (GR). The addition of appropriate amounts of Pd precursors during GR plays a crucial role in the morphology and activity of the ordered Ag@Pd/Ti4O7. Ordered Ag@Pd/Ti4O7 exhibits a half-wave potential of 0.895 V and mass activity of 1.22 A mgPd-1 at 0.9 V, where the latter is approximately 13.7 times higher than that of 20% Pt/C. Excitingly, the zinc-air battery with an ordered Ag@Pd/Ti4O7 catalyst as the cathode shows a maximum power density of 174 mW cm-2. The ordered characteristics of the Ag@Pd alloy and its strong electron transfer with the corrosion-resistant Ti4O7 effectively inhibit the oxidation of Ag, thus improving the catalytic activity and stability. The ingenious combination of ascorbic acid with GR provides a feasible mechanism for the synthesis of ordered bimetallic core-shell structure on oxide surfaces.

Sustainable Synthesis of Dual Single‐Atom Catalyst of PdN4/CuN4 for Partial Oxidation of Ethylene Glycol

AbstractCatalysts assumed that properly designed bimetallic systems would provide superior catalytic performance due to the cooperative effects between two atoms. Dual single‐atom catalyst (DSAC) PdN4/CuN4 is synthesized using a simple, cost‐effective, and efficient electrochemical reduction method. The palladium single‐atom is prepared first by electrochemical reduction of copper phthalocyanine to create defective N4 sites. The new structural feature is characterized by copper reduction from Cu‐N4 coordination and the formation of defected N4 (▫M‐N4) sites, which react with a Pd precursor and form PdN4 on the host surface. The DSAC PdN4/CuN4 technique synergistically improves electrocatalytic performance toward the ethylene glycol oxidation reaction. It possesses excellent glycolate selectivity (above 88%) in an alkaline solution with an onset oxidation potential as low as 0.6 V versus a reversible hydrogen electrode, compared to commercial Pd/C. The DSAC electrocatalyst is characterized by its high current density of 83.92 mA cm−2 and high faradic efficiency value (>80%) for glycolate at 1.0 VRHE. The findings suggest a promising method to synthesize the DSACs in varying transition metals to achieve highly efficient, selective, and environmentally friendly catalysts for different applications.

Interstitial Hydrogen Atom Modified PdPt Nanosheets for Efficient Ethanol Electro-oxidation with High C–C Bond Cleavage Selectivity

Direct ethanol fuel cells (DEFCs) are a type of promising portable power source with low environmental pollution and high energy density. However, the further commercialization of DEFCs is hindered by the incomplete oxidation of ethanol on the electrocatalysts. Herein, we report a successful synthesis of ultrathin PdPtH nanosheets (NSs) for the first time by the in situ formation of interstitial hydrogen atoms accompanied by wet-chemical coreduction of Pd and Pt precursors. The PdPtH NSs possess selectivity of 15.1% related to C–C bond splitting for ethanol complete oxidation to CO2 through the C1 pathway at a low potential, while the contrast selectivity is 4.8% for Pt black, 9.2% for commercial Pd black, and 11.7 for PdH NSs, respectively. Accordingly, the PdPtH NSs exhibited enhanced catalytic activity in comparison to the counterparts. The mass activity toward ethanol oxidation reaction (EOR) of the PdPtH NSs is 5.2 times and 87 times higher than that of commercial Pd and commercial Pt, respectively. The structure stability and growth mechanism of the PdPtH NSs were also investigated. The results of in situ Fourier transform infrared spectra revealed a stronger C–C bond cleavage ability and CO stripping shows the better antipoisoning properties of the PdPtH NSs arising from the cooperation of the PdPt alloy with interstitial H atoms.

Bromide‐Mediated Reduction Kinetics and Oxidative Etching for Manipulating the Twin Structure and Facet of Pd Nanocrystals for Catalysis

AbstractWith Pd as an example, a set of quantitative analyses is designed to shed light on the bromide‐mediated reduction kinetics and oxidative etching in determining the twin structure and facet of Pd nanocrystals. The success of this work relies on the kinetic measurements of Pd(II) precursor reduction and the close examinations of resultant Pd seeds and nanocrystals at different stages of synthesis. We observe there is a clear trend where low, moderate, and high initial Pd(II) reduction rates regulated by Br− ions correspond to the formation of Pd seeds with singly‐twinned, multiply‐twinned, and single‐crystal structures in the nucleation stage, respectively. Our quantitative analyses also suggest the oxidative etching induced by oxygen/Br− pair can selectively remove the multiply‐twinned Pd seeds from the products in the growth stage while leaving behind singly‐twinned or single‐crystal Pd seeds for the evolution into Pd nanocrystals with well‐defined facets in high purity. The mechanistic insights obtained in this work can be extended to the synthesis of Pd@Pd−Pt core−shell nanocubes with high‐index facets, which can be used as excellent electrocatalysts and photocatalysts for hydrogen generation.

Palladium‐Based Metal Organic Frameworks as Heterogeneous Catalysts for C−C Couplings

AbstractAmong the various cross coupling reactions, C−C cross coupling reaction has attracted many researchers to investigate in the last four decades. The continuous, constant, and consistent progress in this field fetched a Noble prize in 2010, showing the importance of this reaction in diversified fields. Among the various transition metals studied for this reaction, Pd is one of the metals that has exhibited the highest activity due to its unique features and reactivity. Although Pd‐based homogeneous catalyst was the preferred choice for many researchers, the field slowly diverted towards the development of Pd‐based heterogeneous catalysts for C−C coupling reactions. This is obviously due to the high cost of Pd precursor, its self‐deactivation. In this context, metal organic frameworks (MOFs) are one of the solid catalysts frequently employed as host matrix for the deposition of Pd(II) salts and Pd nanoparticles. This is due to the widespread possibilities available for the functionalization of MOFs and their stability during the synthetic procedure. This review provides the design and development of Pd‐based MOFs as heterogeneous catalysts for the C−C cross coupling reactions. After a brief introduction on MOFs and the importance of C−C coupling reactions, the main part of the review summarizes the catalytic data with respect to Pd(II) and Pd nanoparticles as active sites. The last section provides our views in this field for the further development in the near future.

Palladium nanoparticles supported on α-zirconium phosphate nanosheets as a highly efficient heterogeneous catalyst for the Heck reaction

BackgroundDevelopment of more efficient catalysts for Heck reaction is an urgent task. Traditionally, palladium-based catalysts have played an important role in the construction of the CC bonds in the Heck reaction. MethodsBy using layered phosphate (α-ZrP) as the host material, a novel composite Pd@ZrP is prepared by assembling the precursor Pd(NH3)42+ with the exfoliated α-ZrP nanosheets followed by in-situ reduction. The Pd nanoparticles (NPs) with an average diameter of 5.17 nm are uniformly dispersed on the surface of the α-ZrP nanosheets, and their particle sizes ranged from 3 to 7 nm. The catalytic performance of the prepared Pd@ZrP composite is evaluated by selecting the Heck reaction of iodobenzene and methyl acrylate as a model reaction. Significant findingsThe Pd@ZrP composite exhibits excellent catalytic efficiency, achieving 95.8% conversion within 30 min and a conversion frequency (TOF) value of 937.3 h–1 at 100 °C. The reaction conditions are optimized in terms of the catalyst amount, the reaction time and temperature. In addition, the composite can be easily recovered by centrifugation and reused five times without a significant decrease in catalytic activity. The superior catalytic behaviors can be attributed to Pd NPs uniformly distributed on the surface of α-ZrP nanosheets, as well as the large specific surface area and the porous structure of Pd@ZrP composite.

New Complex Salts as Precursors of Porous Pd–Ir–Rh Nanoalloys

New Complex Salts as Precursors of Porous Pd–Ir–Rh Nanoalloys

A facile aqueous-phase synthesis method for small PdCu alloy nanocatalysts to enhance electrochemical CO2 reduction reactivity

In a catalytic reaction involving nanoparticles, the particle size is an important factor influencing the reactivity. In this research, small PdCu alloy nanoparticles with an average size of 2.7 nm were easily synthesized by the co-reduction of Pd and Cu precursors using potassium bromide (KBr) as a capping agent to achieve size control in an aqueous phase. When the synthesized 2.7 nm-sized PdCu alloy nanoparticles were applied as an electrocatalyst for CO 2 reduction reaction (CO 2 RR), using a gas diffusion electrode system, Faradaic efficiency (FE) of over 80% for CO with a significantly low H 2 selectivity (≤2% FE) at 100 mA/cm 2 was achieved. The results revealed that the synthesized nanoparticles are highly suitable for CO 2 -to-CO conversion at high current densities. • A mild condition synthetic route to highly crystalline PdCu alloy. • The particle size of the PdCu is easily controlled by adjusting the amount of Kbr. • 2.7 nm-sized PdCu alloy showed enhanced FE for CO and the lowest FE for H 2 production at relatively high current density of 100 mA/cm 2 compared to 3.5 nm PdCu.

Defect-Rich and Single-Crystalline PdCu Ultrathin Nanowires Promoting Ethanol Oxidation Electrocatalysis

Developing high-performance electrocatalysts for the ethanol oxidation reaction (EOR) is greatly significant for the practical application of direct ethanol fuel cells, but it is still unsatisfactory. In this manuscript, we reported a facile aqueous synthesis of PdCu ultrathin nanowires (UNWs) as a highly active and stable electrocatalyst for EOR electrocatalysis. The synthesis relied on the columnar nucleation of PdCu alloys via co-reduction of Pd and Cu precursors in an aqueous solution with a highly hydrophobic dioctadecyldimethylammonium chloride as the structure-directing surfactant. PdCu UNWs featured ultrathin diameter (∼3.2 nm), defect-rich surface (high-index site), single-crystalline structure, and well-alloyed composition. They disclosed the remarkable mass activity of 3.02 A mgPd–1 and the good chronoamperometric and cycling stability for EOR electrocatalysis, both of which are better than its counterpart catalysts and commercial Pd/C. Mechanism studies further confirmed that PdCu UNWs had much better diffusion ability and lower activation energy based on their structural and compositional add-in synergies.