Preparation of platinum-on-carbon catalysts via hydrolytic deposition: Factors influencing the deposition and catalytic properties

Kaprielova, Ksenia M.; Yakovina, Olga A.; Ovchinnikov, Igor I.; Koscheev, S.V.; Lisitsyn, A.S.

doi:10.1016/j.apcata.2012.10.004

Cited by 20 publications

(32 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Chemisorption measurements were performed on an AutoChem II 2920 (Micromeritics) in pulse mode, 36 using CO as the adsorbing gas and He as the carrier gas. The catalyst samples were reduced during preparation and were re-reduced before CO chemisorption under mild conditions.…”

Section: Methodsmentioning

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

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: 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

“…Many places were abundant in Pt particles, but many were depleted of them (Figure 2). An estimation of Pt‐to‐carbon mass ratio from the XPS spectrum of 5Pt/Nor(B) gave a value of 0.12, which exceeds by several times both the nominal value of 0.05 and the corresponding values for 5Pt/Nor samples with adsorbed chloroplatinic acid or hydrolytically deposited Pt oxide21 and signals for the enrichment in Pt of the external surface of the support.…”

Section: Resultsmentioning

confidence: 91%

“…Both calculations and experimental observations ruled out Pt 0 atoms as reaction intermediates in the reduction of Pt 2+ salts in solutions, and the formation of Pt + Pt 2+ dimers was suggested 20. At the same time, carbon supports strongly promote the hydrolysis of chloroplatinate and PtO x particles easily form on the carbon surface 21…”

Section: Resultsmentioning

confidence: 99%

“…We have recently studied the formation of PtO x particles on different carbon surfaces (in the absence of the reductant),21 and there are a number of similarities between the hydrolytic and the reductive deposition: 1) both proceed quickly at neutral pH but decelerate in strongly alkaline mixtures, 2) both are sufficiently rapid only in the presence of carbon, and 3) both show similar dependence on the nature of the support. Although the hydrolytic deposition onto Nor was easy, it was more problematic on AB carbon.…”

Section: Resultsmentioning

confidence: 99%

“… [a] Mass ratio between fractions <50 and >50 μm, as determined after sieving the catalyst; [b] Ratio between Pt content in the finer and coarse fractions; [c] Estimates for the catalyst as a whole by using the formula ( R C ×wt %Pt <50 +wt %Pt >50 )( R C +1) −1 ; [d] Hydrolytic deposition with sodium carbonate in the absence of the reductant 21…”

Section: Resultsmentioning

confidence: 99%

See 2 more Smart Citations

Synthesis of Pt/C Catalysts through Reductive Deposition: Ways of Tuning Catalytic Properties

et al. 2013

View full text Add to dashboard Cite

Characteristic features of Pt/C catalysts prepared through reductive deposition from an aqueous solution have been investigated. The carbon support was found to act as an effective nucleating agent and to ensure the formation of small and predominantly nonaggregated Pt particles, probably through a preliminary formation of oxide nuclei on the carbon surface. The deposition rates could be high enough to provide the location of Pt nanoparticles near the external surface of the support and outside micropores. The depositions onto bare carbon supports and Pt/C samples presynthesized by using another method proved equally effective, which thus opened a route to various types of metal distribution. With the same metal precursor, reductant, and base (H2PtCl6, NaOOCH, Na2CO3), catalytic properties could be influenced through the support, Pt loading, and deposition conditions. In the oxidation of isopropyl alcohol as a model test reaction, alcohol conversion could be as high as 99.7 % and turnover frequencies 80 000 h−1 [H2O, O2, 1 bar (100 kPa), 30 °C].

show abstract

Factors Influencing the Performance of Pd/C Catalysts in the Green Production of Hydrogen from Formic Acid

et al. 2017

View full text Add to dashboard Cite

Formic acid derived from biomass is known to be used for hydrogen production over Pd catalysts. The effects of preparation variables, structure of the carbon support, surface functional composition on the state of Pd, and catalytic properties of the samples in the vapor-phase decomposition of formic acid were studied. In all catalysts derived from Pd acetate, metal particles visible by conventional TEM had similar sizes, but the adsorption capacity towards CO responded strongly to N-doping of the carbon surface. Moreover, a decrease in the CO/Pd values was accompanied by a significant increase in the reaction rate. Taking account of X-ray photoelectron spectroscopy (XPS) and atomic resolution high-angle annular dark-field scanning transmission electron microscopy (HAADF/STEM) data, the trends observed were assigned to a larger fraction of single electron-deficient Pd atoms in the N-doped samples, which do not adsorb CO but interact with formic acid to produce hydrogen. This was confirmed by extended DFT studies. The obtained results are valuable for the development of Pd catalysts on carbon supports for different processes.

show abstract

Preparation of platinum-on-carbon catalysts via hydrolytic deposition: Factors influencing the deposition and catalytic properties

Cited by 20 publications

References 41 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

Synthesis of Pt/C Catalysts through Reductive Deposition: Ways of Tuning Catalytic Properties

Factors Influencing the Performance of Pd/C Catalysts in the Green Production of Hydrogen from Formic Acid

Contact Info

Product

Resources

About