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Multisource Synergistic Electrocatalytic Oxidation Effect of Strongly Coupled PdM (M = Sn, Pb)/N-doped Graphene Nanocomposite on Small Organic Molecules.

Wu P, Huang Y, Kang L, Wu M, Wang Y - Sci Rep (2015)

Bottom Line: It reveals a synergistic electrocatalytic oxidation effect in PdSn/N-doped graphene Nanocomposite.Further, The high dispersion of small nanoparticles, the altered electron structure and Pd(0)/Pd(II) ratio of Pd in catalysts induced by strong coupled the metal alloying and N-doped graphene are responsible for the multisource synergistic catalytic effect in PdM(M = Sn, Pb) /NG catalysts.Finally, the catalytic durability and stability are also greatly improved.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Structural Chemistry; Key Laboratory of design and assembly of functional nanostructures, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, YangQiao West Road 155#, Fuzhou, 350002, P. R. China.

ABSTRACT
A series of palladium-based catalysts of metal alloying (Sn, Pb) and/or (N-doped) graphene support with regular enhanced electrocatalytic activity were investigated. The peak current density (118.05 mA cm(-2)) of PdSn/NG is higher than the sum current density (45.63 + 47.59 mA cm(-2)) of Pd/NG and PdSn/G. It reveals a synergistic electrocatalytic oxidation effect in PdSn/N-doped graphene Nanocomposite. Extend experiments show this multisource synergetic catalytic effect of metal alloying and N-doped graphene support in one catalyst on small organic molecule (methanol, ethanol and Ethylene glycol) oxidation is universal in PdM(M = Sn, Pb)/NG catalysts. Further, The high dispersion of small nanoparticles, the altered electron structure and Pd(0)/Pd(II) ratio of Pd in catalysts induced by strong coupled the metal alloying and N-doped graphene are responsible for the multisource synergistic catalytic effect in PdM(M = Sn, Pb) /NG catalysts. Finally, the catalytic durability and stability are also greatly improved.

No MeSH data available.


Related in: MedlinePlus

CO stripping curves on Pd/G, Pd/NG, PdSn/NG and PdSn/NG in 1 M KOH solution. Scan rate: 50 mV s−1.
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f4: CO stripping curves on Pd/G, Pd/NG, PdSn/NG and PdSn/NG in 1 M KOH solution. Scan rate: 50 mV s−1.

Mentions: All catalysts were loaded onto a glassy carbon electrode for comprehensive evaluation of their catalytic performance, as shown in Figs 3, 4, 5 and Figs S4–S14. The ethylene glycol oxidation reaction (EGOR) on the as-prepared catalysts was performed by using cyclic voltammetry in 1 M KOH + 0.5 M (CH2OH)2 solution. The curves were recorded after a stable response is obtained and the current was normalized with respect to the electrode area. The CV curves of PdSn/NG with different Pd/Sn atomic ratios are exhibited in Fig. S4. The current density of anode oxidation peak at ca. –0.03 V firstly increased from 65.93 to 118.05 mA cm−2 and then fall down to 98.85 mA cm−2 with the increasing Sn content in the catalyst, while the peak potential shifts positively from –0.05 to –0.02 V. The PdSn(2:1)/NG catalyst possesses the highest current density of 118.05 mA cm−2 at the potential of –0.03 V. This result suggests that adding Sn could promote the Pd catalytic activity in ethylene glycol oxidation reaction; but excessive Sn probably leads to exceeded coverage of Pd active sites24. Thus the catalyst activity for ethylene glycol electrooxidation achieves the best as Pd/Sn atomic ratio is 2:1. The currents for EGOR on the Pd/G, Pd/NG, PdSn/G and PdSn/NG catalysts are 26.05, 45.63, 47.59 and 118.05 mA cm−2, respectively, as shown in Fig. 3. It is noted that the activity of the Pd/NG and PdSn/G is higher that of the Pd/G, the higher activity of Pd/NG is resulted from both the electronic effect as well as the smaller and more uniform metal nanoparticles on N-doped graphene than on graphene, while that of PdSn/G is mainly originated from the optimized electron cloud density and valence state of Pd. Surprisingly, the peak current density (118.05 mA cm−2) of PdSn/NG is higher than the sum of peak current densities (45.63 + 47.59 mA cm−2) of Pd/NG and PdSn/G. It reveals a synergistically electrocatalytic oxidation effect exists in PdSn/N-doped graphene nanocomposite, this agrees with the analyses of the XPS data.


Multisource Synergistic Electrocatalytic Oxidation Effect of Strongly Coupled PdM (M = Sn, Pb)/N-doped Graphene Nanocomposite on Small Organic Molecules.

Wu P, Huang Y, Kang L, Wu M, Wang Y - Sci Rep (2015)

CO stripping curves on Pd/G, Pd/NG, PdSn/NG and PdSn/NG in 1 M KOH solution. Scan rate: 50 mV s−1.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4593028&req=5

f4: CO stripping curves on Pd/G, Pd/NG, PdSn/NG and PdSn/NG in 1 M KOH solution. Scan rate: 50 mV s−1.
Mentions: All catalysts were loaded onto a glassy carbon electrode for comprehensive evaluation of their catalytic performance, as shown in Figs 3, 4, 5 and Figs S4–S14. The ethylene glycol oxidation reaction (EGOR) on the as-prepared catalysts was performed by using cyclic voltammetry in 1 M KOH + 0.5 M (CH2OH)2 solution. The curves were recorded after a stable response is obtained and the current was normalized with respect to the electrode area. The CV curves of PdSn/NG with different Pd/Sn atomic ratios are exhibited in Fig. S4. The current density of anode oxidation peak at ca. –0.03 V firstly increased from 65.93 to 118.05 mA cm−2 and then fall down to 98.85 mA cm−2 with the increasing Sn content in the catalyst, while the peak potential shifts positively from –0.05 to –0.02 V. The PdSn(2:1)/NG catalyst possesses the highest current density of 118.05 mA cm−2 at the potential of –0.03 V. This result suggests that adding Sn could promote the Pd catalytic activity in ethylene glycol oxidation reaction; but excessive Sn probably leads to exceeded coverage of Pd active sites24. Thus the catalyst activity for ethylene glycol electrooxidation achieves the best as Pd/Sn atomic ratio is 2:1. The currents for EGOR on the Pd/G, Pd/NG, PdSn/G and PdSn/NG catalysts are 26.05, 45.63, 47.59 and 118.05 mA cm−2, respectively, as shown in Fig. 3. It is noted that the activity of the Pd/NG and PdSn/G is higher that of the Pd/G, the higher activity of Pd/NG is resulted from both the electronic effect as well as the smaller and more uniform metal nanoparticles on N-doped graphene than on graphene, while that of PdSn/G is mainly originated from the optimized electron cloud density and valence state of Pd. Surprisingly, the peak current density (118.05 mA cm−2) of PdSn/NG is higher than the sum of peak current densities (45.63 + 47.59 mA cm−2) of Pd/NG and PdSn/G. It reveals a synergistically electrocatalytic oxidation effect exists in PdSn/N-doped graphene nanocomposite, this agrees with the analyses of the XPS data.

Bottom Line: It reveals a synergistic electrocatalytic oxidation effect in PdSn/N-doped graphene Nanocomposite.Further, The high dispersion of small nanoparticles, the altered electron structure and Pd(0)/Pd(II) ratio of Pd in catalysts induced by strong coupled the metal alloying and N-doped graphene are responsible for the multisource synergistic catalytic effect in PdM(M = Sn, Pb) /NG catalysts.Finally, the catalytic durability and stability are also greatly improved.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Structural Chemistry; Key Laboratory of design and assembly of functional nanostructures, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, YangQiao West Road 155#, Fuzhou, 350002, P. R. China.

ABSTRACT
A series of palladium-based catalysts of metal alloying (Sn, Pb) and/or (N-doped) graphene support with regular enhanced electrocatalytic activity were investigated. The peak current density (118.05 mA cm(-2)) of PdSn/NG is higher than the sum current density (45.63 + 47.59 mA cm(-2)) of Pd/NG and PdSn/G. It reveals a synergistic electrocatalytic oxidation effect in PdSn/N-doped graphene Nanocomposite. Extend experiments show this multisource synergetic catalytic effect of metal alloying and N-doped graphene support in one catalyst on small organic molecule (methanol, ethanol and Ethylene glycol) oxidation is universal in PdM(M = Sn, Pb)/NG catalysts. Further, The high dispersion of small nanoparticles, the altered electron structure and Pd(0)/Pd(II) ratio of Pd in catalysts induced by strong coupled the metal alloying and N-doped graphene are responsible for the multisource synergistic catalytic effect in PdM(M = Sn, Pb) /NG catalysts. Finally, the catalytic durability and stability are also greatly improved.

No MeSH data available.


Related in: MedlinePlus