Evidence for atomically dispersed Pd in catalysts supported on carbon nanofibers

Kochubey, D.I.; Чесноков, В. В.; Malykhin, S. E.

doi:10.1016/j.carbon.2012.02.040

Cited by 36 publications

(21 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…13,32,35 These Ni containing particles were distinctly different from the observed by HAADF/STEM Pt-group metal species in the catalysts, and in contrast to them, they were inactive in the formic acid decomposition reaction. The obtained supports CNFs and N-CNFs (7 wt.% N) were mesoporous with average pore diameters of 8 and 11 nm and Brunauer-EmmettTeller (BET) surface areas of 220 and 200 m 2 g -1 , respectively.…”

Section: Methodsmentioning

confidence: 73%

See 1 more Smart Citation

Single Atoms of Pt-Group Metals Stabilized by N-Doped Carbon Nanofibers for Efficient Hydrogen Production from Formic Acid

et al. 2016

View full text Add to dashboard Cite

Formic acid is a valuable chemical derived from biomass, as it has a high hydrogen-storage capacity and appears to be an attractive source of hydrogen for various applications. Hydrogen production via formic acid decomposition is often based on using supported catalysts with Pt-group metal nanoparticles. In the present paper, we show that the decomposition of the acid proceeds more rapidly on single metal atoms (by up to one order of magnitude). These atoms can be obtained by rather simple means through anchoring Pt-group metals onto mesoporous N-functionalized carbon nanofibers. A thorough evaluation of the structure of the active site by aberration-corrected scanning transmission electron microscopy (ac-STEM) in high-angle annular dark field (HAADF) mode, by CO chemisorption, X-ray photoelectron spectroscopy (XPS) and quantum-chemical calculations reveals that the metal atom is coordinated by a pair of pyridinic nitrogen atoms at the edge of graphene sheets. The chelate binding provides an ionic/electron-deficient state of these atoms prevents their aggregation and thereby leads to an excellent stability under the reaction conditions. Catalysts with single atoms have also shown very high selectivity. Evidently, the findings can be extended to hydrogen production from other chemicals and can be helpful for improving other energy-related and environmentally benign catalytic processes.

show abstract

Section: Methodsmentioning

confidence: 73%

“…Unfortunately, this does not always happen, and single metal atoms can be less active and even inactive in some of the reactions. 13,14 The major applications of single-atom catalysis are currently related to environmental catalysis, e.g. to CO [15][16][17] or NO 18 oxidation, hydrogenation 16,19,20 and partial oxidation 21 reactions.…”

Section: Introductionmentioning

confidence: 99%

Single Atoms of Pt-Group Metals Stabilized by N-Doped Carbon Nanofibers for Efficient Hydrogen Production from Formic Acid

et al. 2016

View full text Add to dashboard Cite

show abstract

“…[1][2][3][4][5][6][7][8] However, synthesis of such single-atom catalyst (SAC) is not trivial, because metal single atoms are often very mobile on surface and tend to aggregate to form clusters or nanoparticles due to high surface free energy, especially under reaction conditions. 2,4,[9][10] Synthesis of SACs from gas phase could be an even greater challenge, since it is usually carried out at elevated temperatures, which would significantly accelerate metal atom aggregations during synthesis.…”

Section: Supporting Informationmentioning

confidence: 99%

Single-Atom Pd₁/Graphene Catalyst Achieved by Atomic Layer Deposition: Remarkable Performance in Selective Hydrogenation of 1,3-Butadiene

et al. 2015

View full text Add to dashboard Cite

We reported that atomically dispersed Pd on graphene can be fabricated using the atomic layer deposition technique. Aberration-corrected high-angle annular dark-field scanning transmission electron microscopy and X-ray absorption fine structure spectroscopy both confirmed that isolated Pd single atoms dominantly existed on the graphene support. In selective hydrogenation of 1,3-butadiene, the single-atom Pd1/graphene catalyst showed about 100% butenes selectivity at 95% conversion at a mild reaction condition of about 50 °C, which is likely due to the changes of 1,3-butadiene adsorption mode and enhanced steric effect on the isolated Pd atoms. More importantly, excellent durability against deactivation via either aggregation of metal atoms or carbonaceous deposits during a total 100 h of reaction time on stream was achieved. Therefore, the single-atom catalysts may open up more opportunities to optimize the activity, selectivity, and durability in selective hydrogenation reactions.

show abstract

“…As mentioned above, all used supports are mesoporous materials. Hence, the considerable increase of the Ru content in the surface layer of the samples with N can be explained by the stronger interaction of Ru with N sites on the external surface of the N‐CNFs bundles that prevents Ru diffusion to the internal volume of the bundles and prevents the incorporation of Ru between graphene layers, which might take place in the undoped sample similar to that found for Pd/CNFs catalysts 23. Therefore, a more uniform distribution of Ru through the support in the undoped sample should be expected.…”

Section: Resultsmentioning

confidence: 53%

Nitro Promoters for Selectivity Control in the Core Hydrogenation of Toluidines: Controlling Adsorption on Catalyst Surfaces

et al. 2014

View full text Add to dashboard Cite

The diastereoselectivity in the hydrogenation of multi‐substituted aromatic ring systems was used as a sensitive tool to gain molecular‐level insight into the reaction pathways on the surface of ruthenium. Here, the hydrogenation of para‐, meta‐, and ortho‐toluidine was studied in detail. The chemoselectivity towards primary or secondary amines depends primarily on the choice of the metal; notably, nitro compounds such as NaNO2 are highly effective promoters for ruthenium catalysts, which significantly increase the chemoselectivity towards primary amines as well as catalytic activity. Lower activation energy and altered diastereoselectivity indicate that in the presence of nitro additives, the substrate molecules are adsorbed in a coordination mode favourable for the hydrogenation of the aromatic ring.

show abstract

Evidence for atomically dispersed Pd in catalysts supported on carbon nanofibers

Cited by 36 publications

References 24 publications

Single Atoms of Pt-Group Metals Stabilized by N-Doped Carbon Nanofibers for Efficient Hydrogen Production from Formic Acid

Single Atoms of Pt-Group Metals Stabilized by N-Doped Carbon Nanofibers for Efficient Hydrogen Production from Formic Acid

Single-Atom Pd₁/Graphene Catalyst Achieved by Atomic Layer Deposition: Remarkable Performance in Selective Hydrogenation of 1,3-Butadiene

Nitro Promoters for Selectivity Control in the Core Hydrogenation of Toluidines: Controlling Adsorption on Catalyst Surfaces

Contact Info

Product

Resources

About

Evidence for atomically dispersed Pd in catalysts supported on carbon nanofibers

Cited by 36 publications

References 24 publications

Single Atoms of Pt-Group Metals Stabilized by N-Doped Carbon Nanofibers for Efficient Hydrogen Production from Formic Acid

Single Atoms of Pt-Group Metals Stabilized by N-Doped Carbon Nanofibers for Efficient Hydrogen Production from Formic Acid

Single-Atom Pd1/Graphene Catalyst Achieved by Atomic Layer Deposition: Remarkable Performance in Selective Hydrogenation of 1,3-Butadiene

Nitro Promoters for Selectivity Control in the Core Hydrogenation of Toluidines: Controlling Adsorption on Catalyst Surfaces

Contact Info

Product

Resources

About

Single-Atom Pd₁/Graphene Catalyst Achieved by Atomic Layer Deposition: Remarkable Performance in Selective Hydrogenation of 1,3-Butadiene