Formation of nanocomposite platinum catalysts on porous silicon

Yashtulov, N. A.; Gavrin, S. S.; Bondarenko, Vitaly; Kholostov, Konstantin; Ревина, А. А.; Флид, В. Р.

doi:10.1007/s11172-011-0068-0

Cited by 7 publications

(5 citation statements)

References 9 publications

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“…A recent report by Liu et al [ 7 ] also showed that the Ag nanoparticles supported on PS chips exert high catalytic reduction on p-nitrophenol. Meanwhile, Yashtulov et al [ 8 ] studied the influence of PS’s porosity and conductivity type on the phase/charge state of Pt in Pt/PS nanocatalyst.…”

Section: Introductionmentioning

confidence: 99%

Surface Characteristics and Catalytic Activity of Copper Deposited Porous Silicon Powder

et al. 2014

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Porous structured silicon or porous silicon (PS) powder was prepared by chemical etching of silicon powder in an etchant solution of HF: HNO3: H2O (1:3:5 v/v). An immersion time of 4 min was sufficient for depositing Cu metal from an aqueous solution of CuSO4 in the presence of HF. Scanning electron microscopy (SEM) analysis revealed that the Cu particles aggregated upon an increase in metal content from 3.3 wt% to 9.8 wt%. H2-temperature programmed reduction (H2-TPR) profiles reveal that re-oxidation of the Cu particles occurs after deposition. Furthermore, the profiles denote the existence of various sizes of Cu metal on the PS. The Cu-PS powders show excellent catalytic reduction on the p-nitrophenol regardless of the Cu loadings.

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Section: Introductionmentioning

confidence: 99%

Surface Characteristics and Catalytic Activity of Copper Deposited Porous Silicon Powder

et al. 2014

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“…This suggests a certain self organization of Pd nanoparticles on the PS surface. 3,4,7, 8 The results 3 of the measurements of the integral inten sity of the characteristic bands of plasmon absorption of Pd nanoparticles (λ 1 = 230-265 nm, λ 2 = 290-320 nm), which were obtained during adsorption on the surface of PS of n and p type of conductivity within 72 hours, are listed in Table 4. Later on the integral intensity changed insufficiently.…”

Section: Resultsmentioning

confidence: 99%

“…7, 8 The PS plates were subjected to anode electrochemical etching in water ethanol solution of HF. During the galvanostatic mode of anodizing the current density was within 20-100 mA cm -2 .…”

Section: Methodsmentioning

confidence: 99%

“…5, 6 The use of catalysts in the form of nano sized particles increase their efficiency and decrease their consumption, that is especially important in case of the metals of platinum group. Previously 7, 8 we described the results of the synthesis and the application of the palla dium, silver and platinum nanocomposite catalysts for the hydrogen air fuel cells (FC).…”

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confidence: 99%

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The formation of palladium nanocomposite catalysts on the porous silicon used as anodes of fuel cells

et al. 2010

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Palladium nanoparticles on the porous silicon were synthesized by radiation chemical reduction in the solution of reversed micelles. The Pd nanoparticles obtained are electron deficient. The porosity, the type of conductivity, the silicon matrix pore geometry, and precur sor parameters influence the size, the shape and the charge state of palladium catalysts. The mechanism of Н 2 and HCOOH electrooxidation on porous silica in the presence of Pd δ+ /Pd redox pair is proposed.The unique properties of the porous silicon (PS) offer the possibility for developing electrocatalytic composites with high surface area (more than 400 m 2 g -1 ) and for preparing specific catalysts in the structure directing porous matrix with the desirable size and shape. 1-4 The low power electric sources of the new generation for elec tronics compatible with the silicon microchips are con structed on the base of catalytically active PS compos ites. 5,6 The use of catalysts in the form of nano sized particles increase their efficiency and decrease their consumption, that is especially important in case of the metals of platinum group. Previously 7,8 we described the results of the synthesis and the application of the palla dium, silver and platinum nanocomposite catalysts for the hydrogen air fuel cells (FC).The development of FC is considered as one of the main breakthrough technologies in the energetics of the 21st century. The efficiency of the direct transforma tion of the chemical energy to the electric energy in the cells achieves 50-70%. The fuel in the PS based FC is hydrogen, methanol, ethanol or formic acid, whereas the oxidant is the oxygen of the air. The reaction products are either H 2 O or H 2 O with СО 2 . In the internal circuit, the ionic electrolyte conductor should provide migration of ions and separation of the fuel reductant and the oxidant. In the modern low temperature FCs the proton exchange membranes are usually utilized as electrolytes. These membranes <0.2 mm thick are prepared from perfluor inated ion exchange polymer permeable to protons. To increase the efficiency of FC operation the development of catalytically active electrodes reactions on anode and cathode is needed.In the development of the novel catalytic systems for the low temperature FC anodes the use of Pd and its composites is at present the most promising option. 2,9The Pd composites possess high catalytic activity in the reactions of oxidation of the widespread fuel types (hydrogen, formic acid, ethanol, etc.) and they are stable toward СО, which is a common catalyst poison in FCs. 9

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“…This is distinct from the earlier reports of metal/PSi composites obtained from aqueous metal salt solutions using metal hydrides or hydrogen as reducing agents, which result in the formation of much larger metal particles (Coulthard et al, 1993 , 2000 ; Coulthard and Sham, 1998 ). Similarly, the surfactant mediated method using sodium borohydride as reducing agent in aqueous-ethanol solution results in the formation of large metal nanoparticles in the range of 10–50 nm (Yashtulov et al, 2011 , 2016 ).…”

Section: Introductionmentioning

confidence: 99%

Porous Nanocrystalline Silicon Supported Bimetallic Pd-Au Catalysts: Preparation, Characterization, and Direct Hydrogen Peroxide Synthesis

et al. 2018

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Bimetallic Pd-Au catalysts were prepared on the porous nanocrystalline silicon (PSi) for the first time. The catalysts were tested in the reaction of direct hydrogen peroxide synthesis and characterized by standard structural and chemical techniques. It was shown that the Pd-Au/PSi catalyst prepared from conventional H2[PdCl4] and H[AuCl4] precursors contains monometallic Pd and a range of different Pd-Au alloy nanoparticles over the oxidized PSi surface. The PdAu2/PSi catalyst prepared from the [Pd(NH3)4][AuCl4]2 double complex salt (DCS) single-source precursor predominantly contains bimetallic Pd-Au alloy nanoparticles. For both catalysts the surface of bimetallic nanoparticles is Pd-enriched and contains palladium in Pd0 and Pd2+ states. Among the catalysts studied, the PdAu2/PSi catalyst was the most active and selective in the direct H2O2 synthesis with H2O2 productivity of 0.5 mol gPd-1 h-1 at selectivity of 50% and H2O2 concentration of 0.023 M in 0.03 M H2SO4-methanol solution after 5 h on stream at −10°C and atmospheric pressure. This performance is due to high activity in the H2O2 synthesis reaction and low activities in the undesirable H2O2 decomposition and hydrogenation reactions. Good performance of the PdAu2/PSi catalyst was associated with the major part of Pd in the catalyst being in the form of the bimetallic Pd-Au nanoparticles. Porous silicon was concluded to be a promising catalytic support for direct hydrogen peroxide synthesis due to its inertness with respect to undesirable side reactions, high thermal stability, and conductivity, possibility of safe operation at high temperatures and pressures and a well-established manufacturing process.

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Formation of nanocomposite platinum catalysts on porous silicon

Cited by 7 publications

References 9 publications

Surface Characteristics and Catalytic Activity of Copper Deposited Porous Silicon Powder

Surface Characteristics and Catalytic Activity of Copper Deposited Porous Silicon Powder

The formation of palladium nanocomposite catalysts on the porous silicon used as anodes of fuel cells

Porous Nanocrystalline Silicon Supported Bimetallic Pd-Au Catalysts: Preparation, Characterization, and Direct Hydrogen Peroxide Synthesis

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