Modern views on the state of platinum in supported catalysts for production of motor fuels

Белый, А. С.; Смоликов, М. Д.; Kir’yanov, D. I.; Удрас, И. Е.

doi:10.1134/s1070363207120298

Cited by 12 publications

(6 citation statements)

References 51 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…to CO [15][16][17] or NO 18 oxidation, hydrogenation 16,19,20 and partial oxidation 21 reactions. Catalysis for energy applications is presented by electrocatalytic reactions 14,22 and by catalytic hydrogen-producing reactions such as reforming of naphtha, 23 formic acid decomposition, 24 and water-gas shift reaction. 12,25 For the production of hydrogen by formic acid decomposition, catalysis with single-atoms and sub-nanometer clusters was reported for gold catalysts.…”

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

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: 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

“…[2][3][4][5] that the activity of catalysts depends on the content of the zeolite, and the area of the maximum yield of the target products (DTMSes) shifts along the temperature scale from 300 to 260°C when the content of mordenite in the support is raised from 10 to 50 wt % upon loading platinum from H 2 PtCl 6 acid and its localization on the surface of Al 2 O 3 crystallites. The selectivity of isomerization then depends solely on the conversion of n heptane.…”

Section: Effect Of the Platinum Precursor On The Isomerization Of N Hmentioning

confidence: 99%

“…It is worth noting that reformate (the product of catalytic reforming and the basic com ponent of gasoline) contains 65-70 wt % aromatic hydrocarbons (including 2-6 wt % benzene), depend ing on the quality of the initial material and the sever ity of the process. The average fraction of reformate at oil refineries in Russia is 50%, and can be as high as 70-75% when there is no catalytic cracking at a plant (i.e., at every other plant) [2,3]. The content of aro matic hydrocarbons and benzene in the reformate thus determines their levels in commercial gasoline.…”

Section: Introductionmentioning

confidence: 99%

Isomerization of n-heptane on Pt/MOR/Al2O3 catalysts

et al. 2014

Self Cite

View full text Add to dashboard Cite

Pt/MOR/Al 2 O 3 catalysts with mordenite zeolite contents of 10 to 50 wt % are prepared. Solutions of H 2 PtCl 6 and [Pt(NH 3 ) 4 ]Cl 2 are used as precursors of Pt. It is shown by means of transmission electron microscopy (TEM) that the localization of platinum on a MOR/Al 2 O 3 mixed support depends directly on the nature of the metal's precursor. The catalysts are tested in the isomerization of n heptane. It is shown that the best samples of catalysts provide yields of the target products (dimethyl and trimethyl substituted isomers of heptanes) on the level of 21 wt % at a temperature of 280°C, while those of a C 5+ stable catalyzate are on the level of 79-82 wt %. The catalysts can be used to improve the environmental friendliness of gasolines by employing them in the isomerization of the 70-105°C fraction of directly distilled gasoline.

show abstract

“…It has been demonstrated [8,9] that due to a strong interaction with the support, the platinum is present as complexes of platinum(II) built into the surface layers of the alumina at the sites of its structural defects. In this case, the active component will form differently on supports with different local structures.…”

Section: Determination Of the Local Structure C-al 2 O 3 Supportsmentioning

confidence: 99%

“…The interaction of metal complexes and alumina via this coordination mechanism involving ligand substitution in the coordination sphere of platinum leads to the formation of PtCl x O y surface compounds [8]. In this case, due to strong interaction with the support, platinum is in the electron deficient (ionic) state with platinum(II) complexes incorporated in the surface layers of alumina at the defect sites [9]. Data on the ionic state of platinum in alumina-platinum catalysts were first reported in [10] and then verified by others [5,11].…”

Section: Introductionmentioning

confidence: 99%

Effect of structural defects in alumina supports on the formation and catalytic properties of the active component of reforming catalysts

Мороз

Zyuzin

Tregubenko

et al. 2013

Reac Kinet Mech Cat

View full text Add to dashboard Cite

The pair distribution function (PDF method) was used to investigate the phase composition and local structure of supports and the model reforming catalysts Pt/c-Al 2 O 3 . The structural modification of support during acidic peptization of aluminum hydroxide with the pseudoboehmite structure was suggested as a possible approach to obtaining highly defective alumina. This modification of c-Al 2 O 3 results in the formation of a greater number of cation vacancies in the octahedral positions of the spinel-like alumina structure. The effect of structural defects in the support on the oxidation state of the active component and catalytic properties of the catalysts was demonstrated. It was found that platinum ions are located in the vacant octahedral positions (defects) of the spinel-like structure of the support. These ionic platinum centers on alumina with higher defect density demonstrated a higher selectivity in the model reaction of n-heptane aromatization as compared to metallic centers which prevail in traditional Pt/c-Al 2 O 3 catalyst.

show abstract

Modern views on the state of platinum in supported catalysts for production of motor fuels

Cited by 12 publications

References 51 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

Isomerization of n-heptane on Pt/MOR/Al2O3 catalysts

Effect of structural defects in alumina supports on the formation and catalytic properties of the active component of reforming catalysts

Contact Info

Product

Resources

About