TEM and XRD investigation of Pd on ultradispersed diamond, correlation with catalytic activity

doi:10.1016/j.mencom.2009.05.006

Mendeleev Communications

Volume 19, Issue 3, May–June 2009, Pages 133-135

https://doi.org/10.1016/j.mencom.2009.05.006 Get rights and content

The relationship between the catalytic activity and Pd particle size in Pd/ultradispersed diamond catalysts is established in the hydrodechlorination of 1,3,5-trichlorobenzene under multiphase conditions.

References (16)

E. Auer et al.
Appl. Catal. A: General
(1998)
X. Tao et al.
Mater. Sci. Eng., B
(1996)
V.L. Kuznetsov et al.
Carbon
(1994)
E.V. Golubina et al.
Appl. Catal. A: General
(2006)
C.A. Marques et al.
J. Mol. Catal. A: Chem.
(1995)
M.A. Aramendia et al.
J. Catal.
(1999)
J. K. Fawell and S.Hunt, Environmental Toxicology, Organic Pollutants, Ellis Horwood, Chichester,...
J. F. McEldowney and S. McEldowney, Environment and the Law, Longman, Harlow,...

There are more references available in the full text version of this article.

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A complementary study on novel PdAuCo catalysts: Synthesis, characterization, direct formic acid fuel cell application, and exergy analysis
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For 10% PdAuCo/MWCNT, two different peaks appear at the (1 1 1), (2 0 0), (2 2 0), and (3 1 1) plane. These peaks can be assigned to PdAu alloys having different bulk compositions, attributed to the formation of heterogeneous alloys with regions of different bulk atomic ratios [16,62–65]. Knecht et al. showed that Pd and Au were also well-mixed as alloys in 1.5 nm particles [66].
At present, Pd containing (10–40 wt%) multiwall carbon nanotube (MWCNT) supported Pd monometallic, Pd:Au bimetallic, and PdAuCo trimetallic catalysts are prepared via NaBH₄ reduction method to examine their formic acid electrooxidation activities and direct formic acid fuel cell performances (DFAFCs) when used as anode catalysts. These catalysts are characterized by advanced analytical techniques as N₂ adsorption and desorption, XRD, SAXS, SEM-EDX, and TEM. Electronic state of Pd changes by the addition of Au and Co. Moreover, formic acid electrooxidation activities of these catalysts measured by CV indicates that particle size changes in wide range play a major role in the formic acid electrochemical oxidation activity, ascribed the strong structure sensitivity of formic acid electrooxidation reaction. PdAuCo (80:10:10)/MWCNT catalyst displays the most significant current density increase. On the other hand, lower CO stripping peak potential obtained for PdAuCo (80:10:10)/MWCNT catalyst, attributed to the awakening of the Pd-adsorbate bond strength down to its optimum value, which favors higher electrochemical activity. DFAFCs performance tests and exergy analysis reveal that fuel cell performances increase with the addition of Au and Co which can be attributed to synergetic effect. Furthermore, temperature strongly influences the performance of formic acid fuel cell.
The role of metal–support interaction in catalytic activity of nanodiamond-supported nickel in selective phenylacetylene hydrogenation
2016, Journal of Catalysis
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Detonation nanodiamond is known to stabilize metal nanoparticles. In our previous study impregnation of ND with Pd(NO3)2 with subsequent H2 reduction provided the formation of Pd nanoparticles less than 8 nm in size on the ND surface, according to TEM data [20]. The presence of Ni nanoparticles in Ni/ND was confirmed by HRTEM study.
Metal precursor coordination and its reduction mechanism in Ni catalysts supported on detonation nanodiamonds (ND) have been studied. TPR demonstrated multistage reduction of NiO supported on ND, which was explained by the presence of two types of Ni species on the ND surface. Weakly bonded Ni species are held on the ND surface by van der Waals forces, whereas strongly bonded ones are chemically bonded to the functional groups on the ND surface. Both NiNi and NiOC scattering paths were found in Ni/ND catalysts using Morlet wavelet analysis of EXAFS data. The ratio of weakly and strongly bonded Ni species in the catalyst was tailored either by removal of functional groups by annealing of ND support in Ar at 900 °C or by calcination of NiO/ND precursor in air at 300 °C. The former resulted primarily in weakly bonded Ni species in the catalyst, while the latter led to strongly bonded ones. These two catalysts demonstrated drastic differences in selective styrene formation upon phenylacetylene hydrogenation: weakly bonded Ni species gave rise mainly to ethylbenzene, while Ni species strongly bonded to the surface through the NiOC bond afforded mainly styrene.
Ultradispersed diamond as an excellent support for Pd and Au nanoparticle based catalysts for hydrodechlorination and CO oxidation
2011, Diamond and Related Materials
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The Pd/UDD catalysts were extremely active in hydrodechlorination (HDC) of chlorinated benzene derivatives in comparing with Pd/C with the same Pd loading. Its activity in HDC of 1,3,5-trichlorobenzene (TCB) was recently described [9,18]. Selectivity of hydrodechlorination of 1,3,5-trichlorobenzene was different for Pd/C and Pd/UDD catalysts as well.
The present study is aimed at the investigation of the catalytic performance of Pd or Au supported on ultradispersed diamond (UDD) catalysts in reductive and oxidative conditions. Very high catalytic activity of Pd or Au supported on ultradispersed diamond (UDD) was observed, in hydrodechlorination and CO oxidation, respectively. Specifically, Pd/UDD shows remarkable selectivity in the hydrodechlorination of 1,3,5-trichlorobenzene (benzene was the main product already at 30% TCB conversion and became the only product after 30 minutes of the reaction), substantially exceeding the performance of Pd supported on activated carbon and commercial 5% Pd/C references. It is proposed that this behavior is linked to the O-containing functional groups at the UDD surface, as detected via IR and EDX/SEM mapping, combined with a very small (6–7 nm by XRD) particle size of UDD support.
Palladium supported on detonation nanodiamond as a highly effective catalyst of the C=C and C≡C bond hydrogenation
2011, Catalysis Communications
Paramagnetic centers in detonation nanodiamonds studied by CW and pulse EPR
2010, Chemical Physics Letters
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However, detailed data of the magnetic resonance parameters as well as of the concentration of the P1-centers in detonation nanodiamonds are absent. Detonation nanodiamonds have been used as effective and stable catalysts [21] and catalyst supports [22]. Therefore the study of the structure as well as the surface properties of such species is of great importance.
Dispersed detonation nanodiamonds have been studied by continuous-wave (CW) and pulse EPR techniques. The spectrum of bulk radicals (g = 2.0025 ± 0.0002, a Lorentz line shape with ΔH_pp = 0.95 ± 0.05 mT) dominated in CW EPR and prevented to record spectra from other paramagnetic species. The pulse EPR-spectrum was the superposition of the distorted P1-center spectrum with parameters (g = 2.0025, A_xx = 2.57 mT, A_yy = 3.08 mT, A_zz = 4.07 mT), the H1-center spectrum (g = 2.0028) and the single line (g = 2.0025, ΔH_pp = 0.40 ± 0.05 mT) from other centers which may be assigned to surface radicals. The concentration of P1-centers has been estimated by CW EPR as 2 ± 1 ppm N.
Development and design of pd-containing supported catalysts for hydrodechlorination
2010, Studies in Surface Science and Catalysis
Citation Excerpt :
UDD possesses high specific surface area, almost 300 m2/g, with several types of carbonyl functional groups predominant on the surface a highly defective structure, super hardness and chemical stability. It was shown by TEM data, palladium particles are well distributed on the surface of UDD and their size lies in relatively narrow range [3]. This fact provides high activity of catalysts supported on UDD in comparison with activity of activated carbon supported catalysts with the same Pd loading in HDC of CB.
Hydrodechlorination (HDC) is a remarkable environment friendly and cost saving alterative to the traditional methods for utilization of chlorinated pollutants. The development of new catalysts and revelation of general approaches to catalysts design are discussed in present work. In this work several directions for catalyst design were considered: (1) change of support nature to influence on a formation of Pd-containing active site; (2) modification of active site by second metal addition; (3) varying of metal deposition method and reduction agent on an active site formation.

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TEM and XRD investigation of Pd on ultradispersed diamond, correlation with catalytic activity

Appl. Catal. A: General

Mater. Sci. Eng., B

Carbon

Appl. Catal. A: General

J. Mol. Catal. A: Chem.

J. Catal.