Controlled Growth of Pt–Au Alloy Nanowires and Their Performance for Formic Acid Electrooxidation

Han, Yu; Ouyang, Yongzhong; Xie, Zhihui; Chen, Jinri; Chang, Fangfang; Yu, Gang

doi:10.1016/j.jmst.2016.04.014

Cited by 24 publications

(10 citation statements)

References 39 publications

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“…In forward scan, the observed I and II oxidation peaks at ca. 0.005 V and 0.16 V are attributed to the FAEO via dehydrogenation, and, generally, the electrocatalytic activities of the catalysts are determined in according to these peaks. The peak III at ca.…”

Section: Resultssupporting

confidence: 86%

“…Furthermore, oxidation peaks showing the FAEO via dehaydrogenation are at the potential of 0.21, 0.16, and 0.15 V for Pd/MWCNT, Pd 50 Ag 50 /MWCNT, and Pd 65.6 Ag 33.6 Cr 0.80 /MWCNT. As shown in Figure , Pd 65.6 Ag 33.6 Cr 0.80 /MWCNT demonstrated a negative shift compared with other catalysts; this indicates that the Pd 65.6 Ag 33.6 Cr 0.80 /MWCNT catalyst is more suitable for FAEO …”

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%

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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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Section: Resultssupporting

confidence: 86%

Section: Resultsmentioning

confidence: 99%

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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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“…As for M@Pt core-shell-structured electrocatalysts, all M atoms are in the subsurface and have no direct contact with adspecies; therefore, the activity of Pt shells is mainly affected by stain and electronic effects [600]. System studies focused on ensemble effects in core-shell-structured electrocatalysts with alloy shells cannot be found in literature for the purpose of this review but similar studies on alloyed [601,602] or decorated [603] electrocatalysts have been carried out by several groups, with the possibility that these investigated ensemble effects in alloy electrocatalysts can be used to explain the ensemble effects in core-shell-structured electrocatalysts.…”

Section: Ensemble Effectmentioning

confidence: 99%

Core–Shell-Structured Low-Platinum Electrocatalysts for Fuel Cell Applications

Wang

Luo

et al. 2018

Electrochem. Energ. Rev.

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Pt-based catalysts are the most efficient catalysts for low-temperature fuel cells. However, commercialization is impeded by prohibitively high costs and scarcity. One of the most effective strategies to reduce Pt loading is to deposit a monolayer or a few layers of Pt over other metal cores to form core-shell-structured electrocatalysts. In core-shell-structured electrocatalysts, the compositions of the core can be divided into five classes: single-precious metallic cores represented by Pd, Ru, and Au; singlenon-precious metallic cores represented by Cu, Ni, Co, and Fe; alloy cores containing 3d, 4d or 5d metals; and carbide and nitride cores. Of these, researchers have found that carbide and nitride cores can yield tremendous advantages over alloy cores in terms of cost and promotional activities of Pt shells. In addition, desirable shells with reasonable thicknesses and compositions have been recognized to play a dominant role in electrocatalytic performances. And recently, researchers have also found that the catalytic activity of core-shell-structured catalysts is dependent on the binding energy of the adsorbents, which is determined by the d-band center of Pt. The shifting of this d-band center in turn is mainly affected by strain and electronic effects, which can be adjusted by adjusting core compositions and shell thicknesses of catalysts. In the development of these core-shell structures, optimal synthesis methods are of primary concern because they directly determine the practical application potential of the resulting electrocatalysts. And in this article, the principles behind core-shell-structured low-Pt electrocatalysts and the developmental progresses of various synthesis methods along with the traits of each type of core and its effects on Pt shell catalytic activities are discussed. In addition, perspectives on this type of catalyst are discussed and future research directions are proposed.

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“…For instance, Lim et al applied a highly negative bias to simultaneously reduce both AuCl 4 − and PtCl 6 2− , leading to the formation of PtAu alloy with micrometer‐sized (or sub‐micrometer‐sized) structures on glassy carbon electrode . Han et al also synthesized PtAu alloy nanowires on gold microelectrodes through coreduction of both AuCl 4 − and PtCl 6 2− ions with an AC sine‐shaped bias . Such success in the synthesis of PtAu alloy structures is ascribed to the nonequilibrium conditions supplied by the electrochemical biases, which provide the driving force to overcome the energy barrier for mixing the two types of immiscible metal atoms.…”

mentioning

confidence: 99%

Synthesis of PtAu Alloy Nanocrystals in Micelle Nanoreactors Enabled by Flash Heating and Cooling

Zhang

Chen

Wang

et al. 2018

Part & Part Syst Charact

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A microwave‐assisted flash heating and cooling strategy has been developed for the rapid synthesis of bimetallic alloy nanocrystals made of immiscible metals in microemulsion micelle nanoreactors. The promising oxygen reduction reaction (ORR) catalysts of PtAu alloy nanocrystals with tunable compositions have been successfully synthesized by using the new strategy. The water‐in‐oil (w/o) microemulsion micelles contain strong microwave‐absorbing species (including metal ion precursors, reducing reagent, water, n‐butanol) and they are surrounded with cyclohexane that barely absorbs microwave. The selective absorption of microwave energy in the micelles enables the rapid production of well‐mixed PtAu alloy melt at extremely high local temperatures while the micelle walls are cooled with the cold pool of cyclohexane to freeze the PtAu alloy melt into PtAu alloy nanocrystals with a uniform distribution of metal atoms. Such flash heating inside micelle containers followed by the flash cooling on the micelle walls results in a non‐equilibrium thermodynamic condition to benefit the formation of alloy nanocrystals composed of two immiscible metals.

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Controlled Growth of Pt–Au Alloy Nanowires and Their Performance for Formic Acid Electrooxidation

Cited by 24 publications

References 39 publications

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

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

Core–Shell-Structured Low-Platinum Electrocatalysts for Fuel Cell Applications

Synthesis of PtAu Alloy Nanocrystals in Micelle Nanoreactors Enabled by Flash Heating and Cooling

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