Highly active Au core @Pt cluster catalyst for formic acid electrooxidation

Liao, Mengyin; Li, Weiping; Xi, Xiping; Luo, Chenglong; Gui, Su; Jiang, Cheng; Mai, Zhaohuan; Chen, Binghong

doi:10.1016/j.jelechem.2017.03.024

Cited by 17 publications

(6 citation statements)

References 32 publications

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“…A dual-pathway mechanism has been proposed for FA oxidation on Pt: the dehydrogenation and dehydration pathway. ,, The dehydrogenation pathway involves direct oxidation of FA to CO 2 , while the dehydration pathway produces CO poisoning species which can only be oxidized at high potential (>0.7 V) . As shown in Table S2, two oxidation peaks are observed at 0.5 and 0.93 V for Pt/C, which are ascribed to the direct oxidation of FA and the oxidation of poisonous intermediates from indirect FA oxidation. , Compared to that of Pt/C, no apparent peak potential shift was observed for Ru@Pt x and Ru( n )@Pt x samples, but their catalytic activity is markedly enhanced. In addition, the enhanced catalytic activity by the crystalline Ru core is much higher than that of the amorphous Ru core, and a volcano-shape dependence of the specific activity of Ru( n )@Pt x and Ru@Pt x nanoparticles on the molar ratio of Pt to Ru and lattice strain of Pt was observed (Figure ), suggesting a remarkable impact of the crystalline Ru core and thickness of the Pt shell on the catalytic activity of core–shell nanostructures.…”

Section: Resultsmentioning

confidence: 99%

Ru@Pt Core–Shell Nanoparticles: Impact of the Atomic Ordering of the Ru Metal Core on the Electrocatalytic Activity of the Pt Shell

Zou

Ning

et al. 2019

ACS Sustainable Chem. Eng.

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Constructing core–shell nanostructures is demonstrated to be an effective strategy to improve catalytic activity of metal nanoparticles. However, the impact of the atomic ordering of the metal core on the performance of the shell remains unexplored. Here, ruthenium–platinum (Ru–Pt) core–shell nanoparticles, with a crystalline and amorphous Ru core of the same diameter and diverse Pt shell thicknesses, are prepared and characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), high-angle annular dark-field scanning transition electron spectroscopy (HAADF-STEM), and CO tripping voltammetry. The well-defined heterostructured Ru–Pt interface and anisotropic growth of the Pt shell on the crystalline Ru core (Ru@Pt x ) were observed, while the amorphous Ru core induces a partial alloy at the Ru–Pt interface and isotropic growth of the Pt shell. The core–shell structure also results in an apparent down-shift of the d-band center of Pt, which dissipates much faster on the amorphous Ru core than on crystalline ones, as demonstrated by the XRD and CO desorption potential. The two sets of core–shell nanoparticles show that a volcano-shape dependence of the catalytic activity on the thickness of the Pt shell and the crystalline Ru core markedly enhanced the catalytic performance and stability toward electro-oxidation of formic acid and ethanol, which is ascribed to the lattice strain of the Pt shell, down-shift of the d-band center, the weakened CO adsorption, and thus alleviated poisoning.

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Section: Resultsmentioning

confidence: 99%

Ru@Pt Core–Shell Nanoparticles: Impact of the Atomic Ordering of the Ru Metal Core on the Electrocatalytic Activity of the Pt Shell

Zou

Ning

et al. 2019

ACS Sustainable Chem. Eng.

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“…3). The interface between the core and shell was not clearly visible, which might be due to the same imaging contrast, the similar electron density and the same crystal structure 31,32 . We performed Fourier transform on the high-resolution structures to obtain the corresponding diffraction patterns.…”

Section: Resultsmentioning

confidence: 95%

Preparation and Characterization of Pt@Au/Al<sub>2</sub>O<sub>3</sub> Core-Shell Nanoparticles for Toluene Oxidation Reaction

张超¹,

李思汉²,

吴辰亮³

et al. 2020

Acta Phys Chim Sin

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Customizing core-shell nanostructures is considered to be an efficient approach to improve the catalytic activity of metal nanoparticles. Various physiochemical and green methods have been developed for the synthesis of core-shell structures. In this study, a novel liquid-phase hydrogen reduction method was employed to form core-shell Pt@Au nanoparticles with intimate contact between the Pt and Au particles, without the use of any protective or structure-directing agents. The Pt@Au core-shell nanoparticles were prepared by depositing Au metal onto the Pt core; AuCl 4− was reduced to Au(0) by H2 in the presence of Pt nanoparticles. The obtained Pt@Au core-shell structured nanoparticles were characterized by transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), high-resolution TEM, fast Fourier transform, powder X-ray diffraction (PXRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), and H2-temperature programmed reduction (H2-TPR) analyses. The EDX mapping results for the nanoparticles, as obtained from their scanning transmission electron microscopy images in the high-angle annular dark-field mode, revealed a Pt core with Au particles grown on its surface. Fourier transform measurements were carried out on the high-resolution structure to characterize the Pt@Au nanoparticles. The lattice plane at the center of the nanoparticles corresponded to Pt, while the edge of the particles corresponded to Au. With an increase in the Au content, the intensity of the peak corresponding to Pt in the FTIR spectrum decreased slowly, indicating that the Pt nanoparticles were surrounded by Au nanoparticles, and thus confirming the core-shell structure of the nanoparticles. The XRD results showed that the peak corresponding to Pt shifted gradually toward the Au peak with an increase in the Au content, indicating that the Au particles grew on the Pt seeds; this trend was consistent with the FTIR results. Hence, it can be stated that the Pt@Au core-shell structure was successfully prepared using the liquid-phase hydrogen reduction method. The catalytic activity of the nanoparticles for the oxidation of toluene was evaluated using a fixed-bed reactor under atmospheric pressure. The XPS and H2-TPR results showed that the Pt1@Au1/Al2O3 catalyst had the best toluene oxidation activity owing to its lowest reduction temperature, lowest Au 4d & 4f and Pt 4d & 4f binding energies, and highest Au 0 /Au δ+ and Pt 0 /Pt 2+ proportions. The Pt1@Au2Al2O3 catalyst showed high stability under dry and humid conditions. The good catalytic performance and high selectivity of Pt@Au/Al2O3 for toluene oxidation could be attributed to the high concentration of adsorbed oxygen species, good low-temperature reducibility, and strong interaction.

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“…The stability of the Pd/MWCNT, Pd 50 Ag 50 /MWCNT, and Pd 65.6 Ag 33.6 Cr 0.80 /MWCNT were tested at optimized electrochemical measurement conditions, and the results were represented in Figure . The starting current is seen to drop rapidly, indicating the accumulation of CO on the surface of Pd 65.6 Ag 33.6 Cr 0.80 /MWCNT, Pd 50 Ag 50 /MWCNT, and Pd/MWCNT . This result supports the abovementioned CV results.…”

Section: Resultsmentioning

confidence: 99%

“…Nevertheless, monometallic Pd should be modified due to CO adsorption on Pd surface coming from CO 2 reduction . Many bimetallic and trimetallic anode catalysts have been investigated in the literature for FAEO. In most of these studies, better performance of multi‐metallic catalysts than monometallic catalysts for FAEO was reported .…”

Section: Introductionmentioning

confidence: 99%

Towards more active and stable PdAgCr electrocatalysts for formic acid electrooxidation: The role of optimization via response surface methodology

et al. 2019

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In this study, multiwall carbon nanotube (MCNT)-supported Pd (Pd/MWCNT) catalysts are prepared by using NaBH 4 reduction method. In order to maximize the oxidation and reduction of H 2 SO 4 , synthesis conditions (Pd ratio, molar ratio of NaBH 4 /K 2 PdCl 4 , volume of deionized water, and duration of agitation) are optimized by using response surface methodology (RSM). The optimum synthesis conditions are determined as 58.2% of Pd by weight, 154.6 molar ratio of NaBH 4 to K 2 PdCl 4 , 19.48 mL of deionized water, and 186.16 min of agitation duration. The effect of electrochemical measurement conditions on the oxidation kinetics of Pd/MWCNT is also investigated by RSM. The optimum electrochemical measurement conditions are found as 10 μL of catalyst mixture, 90°C of H 2 SO 4 solution, and 5.5 M H 2 SO 4 . The Pd/MWCNT, Pd 50 Ag 50 /MWCNT, and Pd 65.6 Ag 33.6 Cr 0.80 /MWCNT catalysts prepared under optimized conditions are characterized by using X-ray diffraction, transmission electron microscopy, N 2 adsorption-desorption, and inductively coupled plasma mass spectrometry. The crystallite sizes of these catalysts are found as 4.85, 5.66, and 5.26 nm for Pd/MWCNT, Pd 50 Ag 50 /MWCNT, and Pd 65.6 Ag 33.6 Cr 0.80 /MWCNT catalysts, respectively. Isotherms of all these catalysts are found to be similar to Type V isotherms with H3 hysteresis loop. The average particle size of Pd 50 Ag 50 / MWCNT and Pd 65.6 Ag 33.6 Cr 0.80 /MWCNT catalysts are determined as 5.2 and 9.2 nm, respectively. Electrochemical performance of as-prepared catalysts is evaluated by using cyclic voltammetry and chronoamperometry. The formic acid electrooxidation (FAEO) activities are found as 18.9, 27.8, and 51.6 mA/cm 2 for Pd/MWCNT, Pd 50 Ag 50 /MWCNT, and Pd 65.6 Ag 33.6 Cr 0.80 /MWCNT, respectively. Pd 65.6 Ag 33.6 Cr 0.80 /MWCNT shows the highest activity and stability. Optimization of synthesis conditions and electrochemical measurement parameters allow us to obtain very good electrochemical activity and stability for FAEO reaction compared with anode catalysts in the literature.

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Highly active Au core @Pt cluster catalyst for formic acid electrooxidation

Cited by 17 publications

References 32 publications

Ru@Pt Core–Shell Nanoparticles: Impact of the Atomic Ordering of the Ru Metal Core on the Electrocatalytic Activity of the Pt Shell

Ru@Pt Core–Shell Nanoparticles: Impact of the Atomic Ordering of the Ru Metal Core on the Electrocatalytic Activity of the Pt Shell

Preparation and Characterization of Pt@Au/Al<sub>2</sub>O<sub>3</sub> Core-Shell Nanoparticles for Toluene Oxidation Reaction

Towards more active and stable PdAgCr electrocatalysts for formic acid electrooxidation: The role of optimization via response surface methodology

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