Polyol Method Research Articles

Resolving optimal ionomer interaction in fuel cell electrodes via operando X-ray absorption spectroscopy

To bridge the gap between oxygen reduction electrocatalysts development and their implementation in real proton exchange membrane fuel cell electrodes, an important aspect to be understood is the interaction between the carbon support, the active sites, and the proton conductive ionomer as it greatly affects the local transportations to the catalyst surface. Here we show that three Pt/C catalysts, synthesized using the polyol method with different carbon supports (low surface area Vulcan, high surface area Ketjenblack, and biomass-derived highly ordered mesoporous carbon), revealed significant variations in ionomer-catalyst interactions. The Pt/C catalysts supported on ordered mesoporous carbon derived from biomass showed the best performance under the gas diffusion electrode configuration. Through a unique approach of operando X-ray Absorption Spectroscopy combined with gas sorption analysis, we were able to demonstrate the beneficial effect of mesopore presence for optimal ionomer-catalyst interaction at both molecular and structural level.

Clustered ultra-small iron oxide nanoparticles as potential T1/T2 dual–modal magnetic resonance imaging contrast agents and application to tumor model

Many studies have been conducted on the use of ultra-small iron oxide nanoparticles (USIONs) (d < 3 nm) as potential positive magnetic resonance imaging (MRI)-contrast agents (CAs); however, there is dearth of research on clustered USIONs. In this study, nearly monodispersed clustered USIONs were synthesized using a simple two-step one-pot polyol method. First, USIONs (d = 2.7 nm) were synthesized, and clustered USIONs (d = 27.9 nm) were subsequently synthesized through multiple cross-linking of USIONs with poly(acrylic acid-co-maleic acid) (PAAMA) polymers with many -COOH groups. The clustered PAAMA-USIONs exhibited very weak ferromagnetism owing to the magnetic interaction between superparamagnetic USIONs; this was evidenced by their appreciable r1= 3.9 s‒1mM‒1and high r2/r1ratio of 14.6. Their ability to function as a dual-modal T1/T2MRI-CA in T1-weighted MRI was demonstrated when they simultaneously exhibited positive and negative contrasts in T1-weighted MRI of tumor model mice after intravenous injection. They displayed positive contrasts at the kidneys, bladder, heart, and aorta and negative contrasts at the liver and tumor.&#xD.

Production of Ag nanowires with high yield and narrow size distribution by promoting nucleation through hot injection and their application to disposable paper electrodes

The polyol method has been the most commonly used technique for fabricating silver nanowires (Ag NWs), wherein additive reagents facilitate precise control over their morphology. In this work, we introduced a straightforward approach to synthesize Ag NWs with minimal impurities and uniform diameter by using hot injection method. The underlying mechanism and final product are evaluated, and the scalable process was optimized to achieve a high yield (∼87.8 %). It was found that the hot injection of a Ag precursor at 170 °C significantly accelerated the reduction of Ag ions. The issue of the uniformity of Ag NWs was addressed by adding an organic halide to control the nucleation rate of Ag. The resulting Ag NWs solution was used to impregnated cellulose paper, forming an enhanced electrical network compared to other substrates. Given the low commercial cost of paper, this approach holds significant potential for widespread use in disposable electrodes. Furthermore, after subjecting the fabricated paper electrodes to various forms of damage, the connected LED bulbs consistently maintained their brightness. This demonstrates the network stability and suitability of these electrodes for flexible applications.

A Flexible Multifunctional Sensor Based on an AgNW@ZnONR Composite Material.

A multifunctional sensor comprising flexible and transparent ultraviolet (UV) photodetectors (PDs) with strain gauges based on Ag nanowire (AgNW)@ZnO nanorods (ZnONRs) was fabricated using a cost-effective, simple, and efficient method. High-aspect ratio silver nanowires were synthesized using the polyol method. An AgNW@ZnONR composite was formed via the hydrothermal method to ensure the multifunctional capability of the flexible sensors. After refining the process parameters, the size of the ZnO nanorods was decreased to fabricate pliable multifunctional sensors using AgNW@ZnONRs. At a deposition of 0.207 g of AgNW@ZnONRs, the sensor achieves its maximum switching ratio and fastest response time under conditions of 2000 μW/cm2 UV optical power density. With a ton (rise time) of 2.7 s and a toff (fall time) of 2.3 s, the ratio of Ion to Ioff current is 1151. Additionally, the sensor's maximum optical current value correlates linearly with UV light's power density. The maximum response current increased from 222.5 pA to 588.1 pA, an increase of 164.3%, when the bending angle was increased from 15° to 90° for the sensor with a deposition of 0.276 g of AgNW@ZnONRs. There was no degradation in the response of the sensors after 10,000 bending cycles, as they have excellent stability and repeatability, which means they can meet the requirements of wearable sensor applications. Therefore, there is great potential for the practical application of multifunctional AgNW@ZnONRs in flexible sensors.

The influence of gamma radiation on the structure and morphology of AgNWs/GO nanocomposites

In this study, AgNWs/GO nanocomposites were prepared by mechanically mixing graphene oxide (GO) synthesized using a modified Hummers' method and silver nanowires (AgNWs) synthesized using a modified polyol method. These nanocomposites were subjected to gamma radiation at three different doses (8, 25, and 50 kGy). Modification of materials by gamma radiation is a very important issue in materials science. The effects of gamma radiation on the structure of the nanocomposites were investigated through X-Ray diffraction (XRD) analyses. Changes in morphology depending on the radiation dose were examined using transmission electron microscope (TEM) images. Elemental analysis was performed before and after irradiation. For GO irradiated at a dose of 25 kGy, the strain and dislocation density values reached their highest levels (ε = 0.065 and σ = 3.33 × 1012 cm−2). Following gamma radiation exposure, the strain and dislocation density of AgNWs showed a non-linear decrease compared to the initial sample. The highest values for both strain and dislocation density were recorded at the 0 kGy dose (ε = 0.0064 and σ = 0.0036 × 1012cm−2). Elemental analysis (EDS) indicated that reduction processes occurred depending on the radiation dose, with the highest reduction observed in the sample irradiated at 25 kGy. Studies indicate that gamma radiation can modify the structural and physical properties of the AgNWs/GO nanocomposite.

Synthesis and characterization of (Gd, Nd) co-doped ceramic materials (Gd0.1NdxCe0.9-xO2-δ x = 0.05, 0.10, 0.15) via polyol method using different hydrolysis ratios

Synthesis and characterization of (Gd, Nd) co-doped ceramic materials (Gd0.1NdxCe0.9-xO2-δ x = 0.05, 0.10, 0.15) via polyol method using different hydrolysis ratios

Efficiently shape-selective synthesis of single crystal silver nanocube with the combination of HNO3/NaCl and reaction time for developing surface enhanced Raman scattering (SERS) substrate

Shape control of noble nanomaterials has garnered significant attention in the past decade because niche applications rely on the relationship between the nanoparticle morphology and optical properties. Although many chemical methods have been reported, there is still a need for improvement in terms of uniformity, yields, and synthesis scale. This work exploited the novel modification approach based on the polyol method to control synthesis to obtain a high amount of single-crystal silver nanocubes (AgNCs) with relatively homogeneous sizes and edge lengths of approximately 100 nm. Furthermore, we have discovered the high effectiveness of controlling temperature conditions to examine the conversion from silver nanocubes to tetrahedron nanoparticles, which had been rarely studied before. These as-prepared AgNCs colloidal solutions were further used to develop the SERS substrate on the glass slide through the facile drop cast method. Additionally, through synthesis using ethylene glycol and redispersed in the ethanol solvent, the obtained AgNCs have a high probability coverage on the glass slide once natural evaporation technique to achieve a remarkable amplification effect and reproducibility behavior. It was explored that these substrates could significantly enhance the Raman signal of 4-mercaptobenzoic acid (4-MBA), which is utilized as the probe molecule to assess the SERS behaviors. The enhancement factor (EF) of the SERS substrates prepared using AgNCs was approximately 3.6 × 106. The presence of 4-MBA could be detected with AgNCs in concentrations ranging from 0.01 to 10 mM, with a limit of detection (LOD) of 8.40 μM and a limit of quantification (LOQ) of 25.46 μM. Through analyzing over 20 different spots on various AgNC substrates, synthesized with similar methods and conditions, the Raman signals of 4-MBA were almost unchanged, with a relative standard deviation (RSD) value of 5.81%, indicating that the SERS signal produced by AgNC substrates was highly reproducible. Based on the results, the SERS nanosubstrates developed with AgNCs could potentially be used to detect trace amounts of other harmful organic compounds.

The role of oxygen in the growth of silver nanowires using the polyol method

Silver nanowires (Ag NWs) are gaining significant interest as a promising material for applications in flexible electronics. However, the growth mechanism of Ag NWs, particularly during the polyol synthesis process, remains unclear due to the complex reduction pathways of ethylene glycol (EG). In this paper, first-principles calculation method was employed to investigate the influence of oxygen during the growth of Ag NWs. Specifically, oxygen affects the decomposition products of ethylene glycol and thus the reducibility of EG. This research aims to reveal the mechanism of oxygen promoting the growth of Ag NWs.

Impregnation of Ce&lt;sup&gt;3+&lt;/sup&gt; in YPO&lt;sub&gt;4&lt;/sub&gt; Lattice for Enhanced Green Emission for Biomedical Applications

Green light-emitting YPO4:Tb3+ and YPO4:Tb3+: Ce3+ nanoparticles were synthesised at low temperatures using the polyol method. The phase purity, micromorphology and luminescence characteristics were studied using Transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier Transfer Infrared absorption spectroscopy (FT-IR) and Photoluminescence spectroscopy (PL). Combined XRD and TEM analysis showed that the YPO4 nanoparticles crystallised into a single phase of tetragonal (I41/amd) structure. For all samples, the emission intensity at λem=543 nm assigned to 5D4→7F5 is more prominent than 5D4→7F6 with a maximum at λem=488 nm, and the asymmetric ratio was calculated and analysed. The asymmetric ratio is strongly correlated with the symmetry around the local environment of Tb3+ ions. A significant increase in the asymmetric ratio is observed with an increase in annealing temperature. The energy transfer from Ce3+ ions to Tb3+ ions was tested by studying the photoluminescence properties of YPO4:Tb3+ and YPO4:Tb3+: Ce3+ nanoparticles and how it results in the improvement of the luminescence intensity. The Ce3+5d−4f and Tb3+5D4→7FJ (J = 6 − 3) transitions were observed.

Antimicrobial Activity of ZnS and ZnO-TOP Nanoparticles Againts Pathogenic Bacteria.

This study aims to synthesize ZnS nanoparticles (NPs) and investigate their biocidal effects, along with those of ZnO-Trioctylphosphine (ZnO-TOP) NPs, on various pathogenic microbes. The NPs were synthesized via the polyol method using the forced hydrolysis of zinc acetate. They were characterized by XRD and TEM. The average sizes of ZnS and ZnO-TOP are 3.63 nm and 16.28 nm, respectively. The antimicrobial activities were assessed using agar-well diffusion, minimum inhibitory concentration (MIC), and biofilm inhibition. The results showed that ZnS and ZnO-TOP NPs have potent antimicrobial activity against all tested pathogen microbes. A zone of maximum inhibition (ZMI) of 20±0.54 and 22±0.26 was observed in the case of ZnS for Acinetobacter baumannii and Candida albicans, respectively. For ZnO-TOP, a ZMI of 20±0.15 and 20±0.19 is obtained for Pseudomonas. aeruginosa ATCC 27853 and A. baumannii, respectively. Percentages of biofilm inhibition at 128 μg/ml were notably high for Enterococcus faecalis (96.83 % with ZnO-TOP and 91.17 % with ZnS) and Staphylococcus aureus (87.27 % with ZnO-TOP and 76.37 % with ZnS). The results suggest that ZnS and ZnO-TOP nanoparticles have promising potential as effective antimicrobial agents, especially against biofilm-forming pathogens, indicating their potential for future use in treating microbial infections.

Photoelectrocatalytic property and DFT calculations of TiO2 with broadened infrared light absorption by Gd2O3:Er3+

In this paper, erbium-doped gadolinium oxide rare earth oxide nanoparticles (Gd2O3:Er3+) with good light absorption capacity from the visible to the infrared region were prepared by polyol method, and then compounded with TiO2 by hydrothermal method. SEM, TEM, XPS, UV–vis and electrochemical workstation were used to study the morphology, structure, UV–vis light absorption and photoelectrochemical (PEC) properties of Gd2O3:Er3+/TiO2. The results showed that the Gd2O3:Er3+ spherical nanoparticles with a particle size of about 15 nm were uniformly distributed on the surface of the TiO2 nanorod array, and the Gd2O3:Er3+/TiO2 nanocomposites had good light absorption capacity in the infrared region. Furthermore, the photocurrent densities of Gd2O3/TiO2 and Gd2O3:Er3+/TiO2 were 2.08 and 2.75 times higher than those of TiO2, respectively, manifesting that the broadening of infrared light absorption can improve the PEC property of TiO2. Meanwhile, the DFT calculation results showed that the energy band of Gd2O3:Er3+/TiO2 was significantly narrower than that of TiO2, indicating that Gd2O3:Er3+/TiO2 had a redshift phenomenon of UV–vis absorption. The calculation results of state density showed that the f orbital of Gd2O3:Er3+ intersected with the d orbital of TiO2, indicating that there is an electron transfer between Gd2O3:Er3+ and TiO2.

Investigating Cu-Site Doped Cu-Sb-S Nanoparticles Using Photoelectron and Electron Paramagnetic Resonance Spectroscopy.

Tetrahedrite (Cu12Sb4S13) and famatinite (Cu3SbS4) are good candidates for green energy applications because they possess promising thermoelectric and photovoltaic properties as well as contain earth-abundant and nontoxic constituents. Herein, X-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS), and electron paramagnetic resonance spectroscopy (EPR) methods examined inherent electronic properties and interatomic magnetic interactions of Cu-site doped tetrahedrite and famatinite nanomaterials. An energy-efficient modified polyol method was utilized for the synthesis of tetrahedrite and famatinite nanoparticles doped on the Cu-site with Zn, Fe, Ni, Mn, and Co. This is the first parallel study of tetrahedrite and famatinite nanomaterials with XPS, UPS, and EPR methods alongside a systematic analysis of dopant-dependent effects on the electronic structure and magnetic interactions for each material. XPS showed that the Cu and Sb species in tetrahedrite and famatinite possess different oxidation states, while UPS characterization reveals larger dopant-dependent shifts in the work function for tetrahedrite nanoparticles (4.21 to 4.79 eV) than for famatinite nanoparticles (4.57 to 4.77 eV). Finally, all famatinite nanoparticles display an EPR signal, indicating trace amounts of paramagnetic Cu(II) present below the detection limit of XPS. For tetrahedrite, EPR signatures were observed only for the Zn-doped and Mn-doped nanoparticles, suggesting signal broadening from Cu-Cu spin exchange or spin-lattice relaxation. This study demonstrates the complementary nature of XPS and EPR techniques for studying the oxidation states of metals in solid-state nanomaterials. Comparing the electronic and magnetic properties of tetrahedrite and famatinite while studying the impact of dopant incorporation will guide future endeavors in designing sustainable, high-performance materials for renewable energy applications.

Silver nanogranules-decorated ZnO hybrid nanostructures with enhanced UV photoresponses

Detecting low-power ultraviolet (UV) light is crucial for practical applications. However, 1D ZnO/Ag based photodetectors (PDs) suffer from high expenses and care due to special operating conditions, posing challenges in capturing weak light signals and response time. To overcome these limitations, we integrate ZnO nanostructures with localized surface plasmon resonance of Ag nanoparticles via a surfactant-free hydrothermal-assisted polyol method, resulting in a notable bandgap reduction. SEM analysis revealed roughly spherical nanostructures for pristine ZnO and a porous structure in ZnO@Ag, around 1.4 µm in size with small agglomerates. XRD patterns showed reduced ZnO diffraction peak intensities in ZnO@Ag, confirming their core-like ZnO morphology. The fabricated ZnO@Ag heterojunction PD on an FTO substrate resulted in notable enhancement of PD performance. The ZnO@Ag heterojunction PD demonstrated a rapid 1.77 s response time, a 0.64 s recovery time and a specific detectivity of 11×107 cmHz1/2W−1, indicating its potential for low-cost and sustainable optoelectronics.

Preparation of Ir/TiO2 Composite Oxygen Evolution Catalyst and Load Analysis as Anode Catalyst Layer of Proton Exchange Membrane Water Electrolyzer.

Electrochemical water splitting is regarded as an emerging green and sustainable hydrogen production technology because of its zero-carbon process. However, the overall cost of anode materials in a proton exchange membrane water electrolyzer (PEMWE) is high due to the use of noble metal Ir. It has been proved that introducing carrier materials to reduce the content of Ir element is a feasible cost-reduction program. Here, the Ir/TiO2 composite material was prepared by the polyol method and used to catalyze the oxygen evolution reaction, which could effectively reduce the load amount of Ir in the membrane electrode assembly (MEA). In addition, the theoretical load of Ir was obtained by model calculation and the polarization curve test and electrochemical impedance spectroscopy (EIS) were used to discuss the relationship between Ir load in MEA and voltage loss and conductivity. The results show that MEA has lower voltage loss and better conductivity as the Ir load is in the range of 0.204-0.304 mgIr/cm2. Altogether, an effective method to reduce the Ir load of PEMWE anode was proposed under the premise comprehensive consideration of both catalyst design and MEA preparation in this work.

Impact of Fe2(MoO4)3 and ZnMoO4 on CO Tolerance of Pt/C catalysts for enhanced methanol electrooxidation efficiency

Success of Pt/C catalyst in electrooxidation of methanol is highly influenced by its ability to withstand the poisoning effects of carbonaceous species adsorbed on the catalytic surface. Covalently bonded CO molecules occlude the active sites of the catalytic surface, impeding methanol adsorption. In this study, Pt/C-based nanocomposite catalysts were synthesized incorporating Fe2(MoO4)3 and ZnMoO4 to form heterojunctions through intermittent microwave-assisted polyol method to augment the CO oxidation pathway by introducing hydroxy groups adsorbed on their surfaces. Thorough characterization of the catalysts elucidated their chemical and phase purity, bonding configurations, and oxidation states, with various electroanalytical techniques employed to probe the mechanism of activity enhancement. Furthermore, the distinctive electron density profiles of these molybdate species have been identified as potential facilitators of methanol adsorption on the platinum surface. Equimolar composition in formulating the composite catalysts yielded a fivefold increase in catalytic activity (with ZnMoO4) and a 1.5-fold increase (with Fe2(MoO4)3). This approach demonstrates promise for tailoring Pt/C catalysts to develop industrially viable CO-tolerant and highly stable electrocatalysts.

Impact of the Different Molecular Weights of Polyethylene Glycol (PEG) Coating Agents on the Magnetic Targeting Characteristics of Functionalized Magnetoresponsive Nanoclusters

In this article, we investigated the influence of molecular weight (Mw) on particle deposition efficiency after PEG-functionalized (polyethylene glycol-PEG) magnetoresponsive magnetic cluster targeting. In this work, the clusters were obtained by the solvothermal polyol method using polyethylene glycol (PEG) as a coating agent. So, we investigated three kinds of magnetoresponsive clusters: MNC-2000, MNC-6000, and MNC-10,000. These clusters were coated with PEG, and had molecular weights (Mw) of 2000 Da, 6000 Da, and 10,000 Da, respectively. The authors propose that the key to achieving maximum efficiency in targeted drug delivery is to deposit a thin, uniform layer of medication that covers the vascular wall in the area of interest. We defined a set of efficiency criteria to focus on the most essential characteristics of the targeting results. These are the obstruction degree, which measures the level of vessel obstruction; the magnet coverage degree, which evaluates the quality of particle deposition along the vessel wall; and the proximal deposition degree, which assesses the effect of pulsatile flow on deposition length. We performed several tests to determine how molecular weight affected these efficiency parameters. These tests examined (a) the effect of the injected cluster quantities, (b) the effect of the magnet distance, and (c) the effect of the injection period. Our findings indicate that an increase in PEG’s molar weight significantly impacts magnetic particle targeting efficiency.

Synthesis and morphology of Ag nanowires by fiber template method

The synthesis of traditional silver nanowires often uses a polyol method. There are many factors that affect the structure of silver nanowires, such as silver ion concentration, type and amount of reducing agent, oxygen concentration, stirring speed, temperature, and time. The synthesis conditions are harsh and difficult to replicate. In this paper, natural fibers and synthetic fibers were used as templates to assist the polyol reduction method to obtain silver nanowires with uniform structure. The effect of fiber types on the structure of silver nanowires were studied, including hemp fibers, wheat straw fibers, tobacco stem fibers, and polycarbonate fibers. Polycarbonate fibers induced the synthesis of silver nanowires with the highest aspect ratio, highest yield, and most uniform diameter distribution. The effect of polycarbonate fibers concentrations on the morphology and conductivity of silver nanowires were also studied. When the polycarbonate mass concentration was 8.5 × 10−4 g/mL, the aspect ratio of silver nanowires was the highest. The effect of polycarbonate fibers length (2 mm\\5 mm\\7 mm) on the morphology of silver nanowires were also studied. When the length of the template polycarbonate fibers was 7 mm, the length to diameter ratio and conductivity of the nanowires obtained are the best. Furthermore, the reaction kinetics of the reaction were studied via multiple sampling of silver nanowire reaction solutions and characterized by using UV–visible spectroscopy and scanning electron microscopy. The synthesis method of silver nanowires using fiber template is simple and fast, and can be used to synthesize silver nanowires with uniform diameter distribution on a large scale, thus solving the bottleneck problem of harsh synthesis conditions for silver nanowires. The resulting silver nanowires were blended with carboxymethyl cellulose to prepare conductive inks, which were coated on paper and cured at 180 °C for 30 min to achieve good conductivity.

Behaviour of Pt10-xRux/C catalysts towards the hydrogen oxidation reaction in acidic medium in the presence of adsorbed CO

Pt10-xRux/C materials are synthesised using a classical polyol method and comprehensively characterised by thermogravimetric analysis, inductively coupled plasma – optical emission spectroscopy, electron transmission microscopy and x-ray diffraction. In N2-saturated electrolyte, the PtRu/C catalysts display lower onset potentials for adsorbed CO (COads) removal than the pure Pt/C one. Although the surface coverages of Pt by Ru are high, the PtRu/C catalysts display higher activity than the Pt/C one towards the hydrogen oxidation reaction (HOR), but the same mechanism occurs on all the catalysts. However, when the surface of the catalysts is saturated by COads, the HOR starts at a lower potential on Pt/C than on PtRu/C; Pt/C displays higher activity toward the HOR in the presence of COads between 0.40 and 0.55 V vs RHE. On Pt/C, a small part of COads desorbs into CO2 from 0.40 V through an Eley-Rideal mechanism, freeing very active Pt sites for the HOR. For potentials higher than 0.55 V vs RHE, the PtRu/C catalysts display higher activity for COads removal through the bifunctional mechanism. Ru atoms also block the most active Pt sites for the COads removal and the HOR.

Vanadium-doped TiO&lt;sub&gt;2&lt;/sub&gt; Adsorbent-Photocatalyst for Organic Dye Treatment

This study focuses on the synthesis of V-doped TiO2 materials using a modified polyol method to enhance their efficiency. The obtained materials were characterized by various methods such as XRD, EDX, FTIR, SEM, TEM-SAED, Raman, and UV-Vis DRS. The results indicated the crystalline anatase phase of TiO2, with spherical morphology and an average size of 30nm. The UV-DRS measurement demonstrated that doped materials have a lower bandgap than the pristine TiO2. The material possesses dual functionality, with adsorption capability and photocatalytic activity applied to treat organic dye contaminants. Evaluation of MB degradation under UV irradiation revealed an exceptional efficiency of up to 99% within a remarkably short duration of 30 minutes. Furthermore, the catalyst exhibited robust recovery efficiency exceeding 99% after 2 regeneration cycles and retention of approximately 80% after four cycles.

One-Pot Synthesis of Pd Nanoparticles Supported on Carbide-Derived Carbon for Oxygen Reduction Reaction.

We explored two methods for synthesizing Pd nanoparticles using three different carbide-derived carbon (CDC) support materials, one of which was nitrogen-doped. These materials were studied for oxygen reduction reaction (ORR) in 0.1 M KOH solution, and the resulting CDC/Pd catalysts were characterized using TEM, XRD, and XPS. The citrate method and the polyol method using polyvinylpyrrolidone (PVP) as a capping agent were employed to elucidate the impact of the support material on the final catalyst. The N-doping of the CDC material resulted in smaller Pd nanoparticles, but only in the case of the citrate method. This suggests that the influence of support is weaker when using the polyol method. The citrate method with CDC1, which is predominantly microporous, led to a higher degree of agglomeration and formation of larger particles in comparison to supports, which possessed a higher degree of mesoporosity. We achieved smaller Pd particle sizes using citrate and NaBH4 compared to the ethylene glycol PVP method. Pd deposited on CDC2 and CDC3 supports showed similar specific activity (SA), suggesting that the N-doping did not significantly influence the ORR process. The highest SA value was observed for CDC1/Pd_Cit, which could be attributed to the formation of larger Pd particles and agglomerates.