Iron Oxide-Carbon Black Promotional Effect on Palladium Nanoparticles Toward Ethylene Glycol Oxidation in Alkaline Medium: Experimental and Computational Studies (original) (raw)
Related papers
Fuel, 2025
The study involved the conversion of Palladium (Pd) and Ruthenium (Ru) metal-supported carbon black (CB) into a hybrid nano electrocatalyst using the microwave synthesis method. Among the four tested catalysts (Pd/CB, Pd1Ru1, Pd1Ru2, and Pd2Ru1), Pd2Ru1 electrocatalyst demonstrated the most effective performance for ethylene glycol electrooxidation (−0.51 V onset potential, 0.13 mA/cm2 current density and −0.21 V anodic peak potential). The physical and chemical properties of the hybrid electrocatalysts were characterized using optical and electrochemical techniques. Additionally, the electrochemical test indicated that Pd2Ru1 exhibited superior poisoning resistance and improved electrochemical stability compared to other tested materials. Also, the catalyst generated close to 0.055 A hydrogen production current while the presence of ethanol enhanced the oxidative current. The performance of the cell at two different temperatures (22 and 56 °C) was also elucidated with up to 0.87 and 0.57 V voltage outputs respectively. The study revealed the potential of Pd2Ru1 as an efficient anodic electrocatalyst in the ethylene glycol direct fuel cell assemblies.
Journal of Electroanalytical Chemistry, 2023
Two types of Cu-modified Pd catalysts supported on high area carbon were prepared: Pd nanoparticles modified with a sub-monolayer of underpotentially deposited Cu (Cu@Pd/C) and Pd-Cu alloy nanoparticles (Pd-Cu/C), and examined for the ethanol oxidation reaction (EOR) in alkaline solution. The catalysts were characterized by energy-dispersive X-ray spectroscopy, X-ray diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy, as well as cyclic voltammetry. As reference catalysts, Pd/C and Pt/C were used. The electrochemically active surface area of all samples was determined from CO ads and Cu upd desorption and Pd oxide reduction, and used to assess their intrinsic activity for EOR. Intimate contact of Pd with Cu atoms enhanced its activity, regardless of the type of bimetal catalyst. The atomic Pd:Cu ratio between 2:1 and 4:1 appears to be optimal for high activity. The most active catalyst under the potentiodynamic conditions was Cu@Pd/C with θ(Cu) = 0.21,although Pd-Cu/C was superior during the potentiostatic test. All bimetallic catalysts surpassed Pd/C in mass activity. The EOR activity of Pt/C was higher compared to Pd-based catalysts at low potentials, both in terms of specific and mass activity, but with a significant decline over a 30-min potentiostatic stability test.
Chemistry of Materials, 2024
Renewable energy systems have gained remarkable attention as potential green energy sources with escalating energy demand and environmental issues. Direct alcohol fuel cells are potential energy sources with quick start-up, zero emissions, and high power density. However, current electrocatalysts' poor efficiency and catalytic activity hinder their commercialization. In this study, Pd−Nb metal nanoparticles (MNPs) supported on carbon nano-onions (CNOs) were synthesized using the polyol method for the electro-oxidation of isopropanol and ethanol in an alkaline medium. An inexpensive CNO support was synthesized using the soot-based approach. High-resolution transmission electron microscopy analysis confirmed the successful synthesis of CNOs with a quasi-spherical structure and concentric rings resembling an onion. The Fourier transform infrared spectroscopy analysis confirmed the presence of oxygen moieties on the surface of the CNOs, which were used to anchor the MNPs to the surface of the support. The X-ray photoelectron spectroscopy analysis confirmed the composition of the electrocatalysts and the presence of Pd and Nb in different oxidation states. The synthesized Pd−Nb/CNOs exhibited high catalytic activity and stability for isopropyl alcohol and ethanol electro-oxidation. The addition of Nb to Pd reduced the loading of Pd, thus reducing the cost of the electrocatalyst and improving the physicochemical properties and electrocatalytic activity of Pd toward isopropanol and ethanol electro-oxidation. The increased electrocatalytic activity of Pd−Nb/CNOs is attributed to the increased active sites on the surface of the MNPs and the synergistic effects arising from the CNO support and the Pd−Nb MNPs.
Electrocatalysis, 2019
Bimetallic Pd/SnO 2 nanoparticle electrocatalysts on metal organic framework-derived carbon (MOFDC) were successfully synthesized using microwave-assisted strategies and explored for ethanol oxidation reaction (EOR) in alkaline solution. The materials were thoroughly characterized using XRD, XPS, TEM, and Raman. TEM showed that Pd/SnO 2 /MOFDC gave the least average particle size of 5.5 nm compared to its counterparts on carbon black (CB). The Pd/SnO 2 /MOFDC gave the best electrocatalytic performance in terms of high electrochemical active surface area (ECSA) of 962 cm 2 mg −1 , low onset potential and overpotential for EOR, and high current density (j) of four times more than those of the Pd/CB electrocatalyst. In addition, Pd/ SnO 2 /MOFDC showed superior kinetic parameter (in terms of the Tafel slope (b) = 216.1 ± 8 mV dec −1) and least combined resistance (R = R s + R ct). These results show that the Pd/SnO 2 /MOFDPC nanoparticle electrocatalyst is promising for EOR with improved electrocatalytic properties for application in direct ethanol fuel cell (DEFC).
Highly Active Palladium Nanocatalysts for Low-Temperature Carbon Monoxide Oxidation
Polytechnica, 2019
The noble metal catalysts are most commonly considered to be used in an automobile as a catalytic converter. Palladium (Pd) is a highly active catalyst for carbon monoxide (CO) oxidation in platinum group metals. It is very active for low-temperature CO oxidation if dispersed on suitable metal oxides and composite oxides. The oxidized Pd metal nanocatalyst has been applied more actively than the completely reduced particles. The performance of Pd oxide nanocatalysts strongly depends upon the surface structure, number of active sites and various Pd-O interactions. Palladium is an ideal catalyst not only for the automobile industry through cross-coupling reactions but also for low-temperature catalytic oxidation of CO. The Pd metal is more resistant for sulfur and potassium poisoning, and they are chemically sensitive and degraded rapidly in the presence of fuel impurities. The higher activity of Pd nanocatalyst was attributed to the small particle size and higher dispersion over Pd support. The chemisorptions of CO on Pd catalysts were studied in this review. The results obtained from this study will provide the scientific basis for the future design of Pd-based oxidation catalysts.
Oxygen kinetics and mechanism at electrocatalysts on the base of palladium–iron system
Electrochimica Acta, 2007
Binary nanodispersed carbon XC72 supported PdFe catalysts with different atomic palladium-to-iron ratios are synthesized and studied in oxygen reduction reaction in acid solution at 60 • C. The Pd:Fe ratio was well controlled by the initial concentrations of Pd and Fe in the precursor solutions. The nanoparticles were characterized by transmission electron microscopy, X-ray diffractometry and X-ray photoelectron spectroscopy. The optimum Pd:Fe ratio for this reaction was determined to be 3:1.
Catalytic oxidation of carbon monoxide over supported palladium nanoparticles
Applied Nanoscience, 2015
Catalytic oxidation of CO with ozone had been studied over Al 2 O 3 and SiO 2 supported Pd nanoparticles which was synthesized by two different methods. The polyol method mainly resulted in highly dispersed Pd particles on the support, while the impregnation method resulted in agglomeration Pd particles on the support. Supported Pd nanoparticles synthesized from PdCl 2 in the presence of poly (N-vinylpyrrolidone) (PVP) by chemical reduction. The catalysts were characterized by X-ray diffraction, N 2 BET surface area, pore size distributions, CO chemisorption, TEM and H 2 -temperature programmed reduction. The physico-chemical properties were well correlated with activity data. Characterizations of XRD and TEM show that the surface Pd nanoparticles are highly dispersed over Al 2 O 3 and SiO 2 . The catalytic activity was dependent upon ozone/CO ratio, contact times, and the reaction temperature. The extent of carbon monoxide oxidation was proportional to the catalytically ozone decomposition. The PVP synthesized Pd/A 2 O 3 catalyst had been found to be highly active for complete CO removal at room temperature. The higher activity of the nanocatalyst was attributed to small particle size and higher dispersion of Pd over support.
Physical Chemistry Chemical Physics, 2013
Palladium based nano-alloys are well known for their unique electrocatalytic properties. In this work, a palladium-decorated FeCo@Fe/C core-shell nanocatalyst has been prepared by a new method called microwave-induced top-down nanostructuring and decoration (MITNAD). This simple, yet efficient technique, resulted in the generation of sub-10 nm sized FeCo@Fe@Pd nanocatalysts (mainly 3-5 nm) from a micron-sized (0.21-1.5 mm) FeCo@Fe/C. The electrocatalytic activities of the core-shell nanocatalysts were explored for methanol oxidation reaction (MOR) and oxygen reduction reaction (ORR) in alkaline medium. A negative shift of 300 mV in the onset potential for MOR was observed, with a current thrice that of the Pd/C catalysts. A very low resistance to electron transfer (R ct ) was observed while the ratio of forward-to-backward oxidation current (I f /I b ) was doubled. The overpotential of ORR was significantly reduced with a positive shift of about 250 mV and twice the reduction current density was observed in comparison with Pd/C nanocatalysts with the same mass loading. The kinetic parameters (in terms of the Tafel slope (b) = À59.7 mV dec À1 (Temkin isotherm) and high exchange current density ( j o ) = 1.26 Â 10 À2 mA cm À2 ) provide insights into the favorable electrocatalytic performance of the catalysts in ORR in alkaline media. Importantly, the core-shell nanocatalyst exhibited excellent resistance to possible methanol cross-over during ORR, which shows excellent promise for application in direct alkaline alcohol fuel cells (DAAFCs).
Hydrogen, Fuel Cell & Energy Storage, 2016
Palladium nanoparticles supported on carbon black powder (Vulcan XC-72) nanocomposite (Pd/C) were synthesized as the catalyst for the anodic oxidation of glucose for use in a direct glucose alkaline fuel cell (DGAFC). Characterization of the catalyst was carried out using physical and electrochemical methods. It was observed that Palladium nanoparticles are uniformly dispersed onto the carbon black powder nanocomposite support. The catalytic properties of the catalyst for glucose electro-oxidation were studied using electrochemical methods such as cyclic voltammetry and chronoamperometry. Cyclic voltammetry shows that this catalysts exhibited high electro catalytic activity for glucose oxidation. The Pd/Vulcan XC-72 /glassy carbon electrode exhibited a well-defined catalytic oxidation peak current increasing linearly with an increase in the glucose concentration in the range of 10 mM to 60 mM. Chronoamperometry indicated that Pd/Vulcan XC-72 exhibits a steady state activity for glucose oxidation. Results show that the prepared Pd/Vulcan XC-72 is an effective anodic catalyst toward glucose electro-oxidation. Therefore, this electrode is a good candidate for application in direct glucose alkaline fuel cells.