Surface characterization and catalytic properties of supported tungsten and platinum-tungsten carbide and oxycarbide

Katrib, A.; Hemming, F.; Wehrer, P.; Hilaire, L.; Maire, G.

doi:10.1007/bf01379577

Cited by 19 publications

(13 citation statements)

References 15 publications

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“…For a solid catalyst, the heterogeneous catalytic reaction takes place on its surface. Actually, even on the surfaces of tungsten carbide and metallic tungsten catalysts, there exist layers of tungsten oxide, which are formed in an oxidation atmosphere or during the hydrothermal reaction [94][95][96]. Therefore, it cannot be excluded that the tungsten oxide layers on the tungsten carbide or metallic tungenic catalysts also play some important roles in the CEG process.…”

Section: Tungsten Acid Based Composite Catalystsmentioning

confidence: 99%

One-pot catalytic conversion of cellulose to ethylene glycol and other chemicals: From fundamental discovery to potential commercialization

Zheng

Pang

Wang

et al. 2014

Chinese Journal of Catalysis

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The one-pot catalytic conversion of cellulose to ethylene glycol (CEG) is a highly attractive way for biomass utilization to lessen the consumption of fossil energy resources. In this paper, we reviewed the disclosure of the CEG process and the rapid progress in the development of highly efficient and robust catalysts for it. Based on our study of tungstenic catalysts, we discuss the reaction mechanism, in which the reaction routes, catalyst states, and catalytic roles of the tungsten species and hydrogenation sites in the cascade reactions are understood clearly. With future applications in mind, the conversion of raw cellulosic biomass and the strategy to develop an efficient CEG process for commercialization are discussed, and a model where the CEG process is incorporated into a bio-refinery process of acetone-n-butanol-ethanol (ABE) production is presented.

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Section: Tungsten Acid Based Composite Catalystsmentioning

confidence: 99%

One-pot catalytic conversion of cellulose to ethylene glycol and other chemicals: From fundamental discovery to potential commercialization

Zheng

Pang

Wang

et al. 2014

Chinese Journal of Catalysis

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“…4 is consistent with 4f 5/2 and 4f 7/2 doublets of tungsten in the W 6+ and W 5+ oxidation states. [64][65][66][67] Metallic tungsten (W) and tungsten carbide (WC) components were not observed. Carbon peak deconvolution yields signals for free carbon and carbon bonded to oxygen with BE values at 284.4 eV and 285.4 eV, respectively.…”

Section: Materials Characterizationmentioning

confidence: 99%

“…Carbon peak deconvolution yields signals for free carbon and carbon bonded to oxygen with BE values at 284.4 eV and 285.4 eV, respectively. 65,66,68 The O 1s peak with a BE at 530.7 eV is from WO x 68-70 and a smaller peak at 531.7 eV arises from oxygen bound to carbon. As shown in the SEM images in Fig.…”

Section: Materials Characterizationmentioning

confidence: 99%

Partially fluorinated oxo-alkoxide tungsten(vi) complexes as precursors for deposition of WO_x nanomaterials

et al. 2014

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The partially fluorinated oxo-alkoxide tungsten(VI) complexes WO(OR)4 [4; R = C(CH3)2CF3, 5; R = C(CH3)(CF3)2] have been synthesized as precursors for chemical vapour deposition (CVD) of WOx nanocrystalline material. Complexes 4 and 5 were prepared by salt metathesis between sodium salts of the fluoroalkoxides and WOCl4. Crystallographic structure analysis allows comparison of the bonding in 4 and 5 as the fluorine content of the fluoroalkoxide ligands is varied. Screening of as a CVD precursor by mass spectrometry and thermogravimetric analysis was followed by deposition of WOx nanorods.

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“…Additionally, two small carbon-oxygen peaks associated with all samples aligned with the binding energies expected for C-O (286.2 eV) and carbonate (289.5 eV), which are also adventitious species. 21 The peak in the WC control sample that is attributed to tungsten carbide species (282.7 eV) 22,23 was not detected in either the WP bulk or WP nanoparticle samples. Indeed, the WP sample did not exhibit a measurable peak in the metal carbide region, suggesting that the observed HER activity of the WP/Ti electrode is inherent to WP and not likely to be attributable to WC impurities.…”

mentioning

confidence: 94%

Electrocatalytic hydrogen evolution using amorphous tungsten phosphide nanoparticles

et al. 2014

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Amorphous tungsten phosphide (WP), which has been synthesized as colloidal nanoparticles with an average diameter of 3 nm, has been identified as a new electrocatalyst for the hydrogen-evolution reaction (HER) in acidic aqueous solutions. WP/Ti electrodes produced current densities of À10 mA cm À2 and À20 mA cm À2 at overpotentials of only À120 mV and À140 mV, respectively, in 0.50 M H 2 SO 4 (aq).Despite its scarcity and high cost, platinum is one of the most widely used catalysts for chemical reactions that underpin many clean energy technologies, including fuel cells and solar fuel generators. 1,2 For example, water electrolysis relies on the hydrogen-evolution reaction (HER), which in acidic solutions involves the electrocatalytic reduction of protons to molecular hydrogen. 3 Pt is an exceptional HER electrocatalyst, producing large cathodic current densities at low overpotentials. 3,4 Recently, several new acid-stable HER electrocatalysts have been identified as less expensive and more Earth-abundant alternatives to Pt, including MoS 2 , 5,6 CoSe 2 , 7 Co 0.6 Mo 1.4 N 2 , 8 Ni 2 P, 9,10 CoP, 11,12 and MoP. 13 Each of these systems represents an important development in the search for non-noble-metal HER electrocatalysts, which is important for global scalability where cost and performance must both be considered. Each unique catalyst offers a distinct combination of structure, composition, and properties that collectively can provide useful insights for predicting new catalytic materials and for beginning to interrogate the mechanisms by which they function.We report herein the colloidal synthesis of uniform amorphous tungsten phosphide (WP) nanoparticles with average diameters of 3 nm that remain amorphous upon heating beyond 450 1C. The amorphous tungsten phosphide nanoparticles are also active and acid-stable HER electrocatalysts, representing a new addition to the growing library of nonnoble-metal materials that catalyze the HER. These WP nanoparticles add to an important family of known tungsten-based HER catalysts as well, including WS 2 , 14 WC, 15 and W 2 N. 16 Interestingly, WP is also a known hydrodesulfurization (HDS) catalyst. 17 HDS and HER are distinct catalytic processes, but the reversible binding and dissociation of H 2 represents a possible mechanistic commonality. 3,18,19 The discovery that WP catalyzes the HER further strengthens the hypothesis that known HDS catalysts offer viable targets for active HER catalysts.To synthesize the amorphous WP nanoparticles, W(CO) 6 and trioctylphosphine (TOP) were heated to 320 1C for 2 h in squalane. (See ESI † for complete experimental details. Caution: This reaction should be considered to be highly flammable and corrosive, as it has the potential to liberate phosphorus, which is highly pyrophoric. Therefore, it should only be carried out under rigorously air-free conditions by appropriately trained personnel.) Fig. 1a and Fig. S1 (ESI †) show a transmission-electron microscopy (TEM) image of the isolated product, which formed quasi-spherical parti...

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Surface characterization and catalytic properties of supported tungsten and platinum-tungsten carbide and oxycarbide

Cited by 19 publications

References 15 publications

One-pot catalytic conversion of cellulose to ethylene glycol and other chemicals: From fundamental discovery to potential commercialization

One-pot catalytic conversion of cellulose to ethylene glycol and other chemicals: From fundamental discovery to potential commercialization

Partially fluorinated oxo-alkoxide tungsten(vi) complexes as precursors for deposition of WO_x nanomaterials

Electrocatalytic hydrogen evolution using amorphous tungsten phosphide nanoparticles

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Surface characterization and catalytic properties of supported tungsten and platinum-tungsten carbide and oxycarbide

Cited by 19 publications

References 15 publications

One-pot catalytic conversion of cellulose to ethylene glycol and other chemicals: From fundamental discovery to potential commercialization

One-pot catalytic conversion of cellulose to ethylene glycol and other chemicals: From fundamental discovery to potential commercialization

Partially fluorinated oxo-alkoxide tungsten(vi) complexes as precursors for deposition of WOx nanomaterials

Electrocatalytic hydrogen evolution using amorphous tungsten phosphide nanoparticles

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Product

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Partially fluorinated oxo-alkoxide tungsten(vi) complexes as precursors for deposition of WO_x nanomaterials