• Applied Chemistry for Engineering
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• v.18 no.6
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• pp.552-556
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• 2007

In this study, noble metals (Pd, Ru, Ir) were supported to $TiO_2$ catalyst. In order to distribute metals uniformly, $H_2O-H_2$ pretreatment technique was used. Xylene, toluene, and MEK were used as reactants. The monometallic or bimetallic catalysts were prepared by the excess wetness impregnation method and were characterized by XRD, and XPS analysis. Pd-Ru, Pd-Ir bimetallic catalysts had multipoint active sites which improved the range of Pd metal state. Bimetallic catalysts had a higher conversion of VOCs than that of monometallic one. The effect of $H_2O-H_2$ pretreatment technique was the enhancement of uniform distribution of Pd particles and promotion of catalytic efficiency. In this study, addition of Ru and Ir metals to Pd promoted oxidation conversion of VOCs. In addition, $H_2O-H_2$ pretreatment promoted removal efficiency of VOCs on the $TiO_2$ support.

• Analytical Science and Technology
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• v.21 no.6
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• pp.562-568
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• 2008

A novel two-dimensional cadmium(II)-nickel(II) bimetallic host clathrate, $[Cd{NH_2CH_2CH_2OH}_2Ni(CN)_4]{\cdot}3C_6H_5NH_2{\cdot}H_2O$, 1, has been synthesized and structurally characterized by X-ray single crystallographic method. The clathrate 1 crystallizes in the monoclinic system, space group $P2_1/c$ with a = 14.370(3), b = 7.728(1), c = 28.172(4) ${\AA}$, ${\beta}=97.58(1)^{\circ}$, V = 3101.1(9) ${\AA}^3$, Z = 4. The host framework of the clathrate 1 is built of the cyanide bridges between octahedral Cd(II) atom and square planar Ni(II) atom. The octahedral Cd atoms ligated by two 2-aminoethanol molecules and four cyanide ligands bridged with square planar Ni atoms. The Ni atoms bridges to four Cd atoms via cyanides is made up of puckered quadrangles of composition $\{CdNi(CN)_2\}_2$, all edges are shared. This cyanide bridges form an infinite two-dimensional host networks stacking along b axis. 2-Aminoethanol ligands bond to Cd atom through N atom as a monodentate ligand in the axial position and four cyanides take an equatorial plane with all in trans-configurations. The aniline guest molecules and water molecules are located in between the host layer sheets, respectively.

• Proceedings of the Korean Vacuum Society Conference
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• 2009.08a
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• pp.323-323
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• 2009

• Proceeding of EDISON Challenge
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• 2014.03a
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• pp.359-370
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• 2014

두 가지 서로 다른 원소를 포함한 나노 크기의 금속클러스터가 여러 화학반응의 효과적인 촉매로 각광받고 있다. 그래서 본 연구에서는 분자동역학을 이용하여 48개로 구성된 Au-Pd 나노 금속 클러스터의 다양한 구조와 상전이 현상을 살펴보고자 한다.

• Bulletin of the Korean Chemical Society
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• v.15 no.9
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• pp.699-701
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• 1994

• Bulletin of the Korean Chemical Society
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• v.33 no.3
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• pp.906-910
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• 2012

Hollow gold-silver bimetallic nanoparticles (AuAg-HNPs) have been synthesized and their optical and structural properties were characterized. Initially Ag nanoparticles (Ag-NPs) were prepared using poly(ethylenimine) (PEI) as a reducing and a stabilizing agent simultaneously. AuAg-HNPs could then be synthesized via galvanic replacement reaction in a PEI aqueous solution by reacting sacrificial Ag template with a precursor compound of Au, i.e., $HAuCl_4$. Due to the presence of abundant amine functional groups in PEI, which could act as the dissolving ligand for AgCl, the precipitation problem of $Ag^+$ in the presence of Cl from $HAuCl_4$ salt was avoided. On this basis, the relatively high concentrations of $HAuCl_4$ and PEI-stabilized Ag nanoparticles could be used for the fabrication of AuAg-HNPs. Because of their increased surface areas and reduced densities, the AuAg-HNPs were expected and confirmed to outperform their solid counterparts in applications such as catalysis for the reduction of 4-nitrophenol in the presence of $NaBH_4$.

• Journal of Electrochemical Science and Technology
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• v.11 no.3
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• pp.238-247
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• 2020

Some nano structured bimetallic NiPd electrocatalysts were electrodeposited on glassy carbon electrodes using a double potential step chronoamperometry. The morphology of the electrodeposited samples was investigated by field emission-scanning electron microscopy, while their compositions were evaluated using energy dispersive X-ray spectroscopy. It was observed that the electrodeposited samples contained a low Ni content, in the range of 0.80 - 7.10%. The electrodeposited samples were employed as the anode electro-catalysts for the oxidation of sodium borohydride in NaOH solution (1.0 M) using cyclic voltammetry, chronoamperometry, rotating disk electrode, and impedance spectroscopy. The number of exchanged electrons, charge transfer resistances, apparent rate constants, and double layer capacitances were calculated for the oxidation of borohydride on the prepared catalysts. According to the results obtained, the NiPd-2 sample with the lowest Ni content (0.80%), presented the highest catalytic activity for borohydride oxidation compared with the other NiPd samples as well as the pure Pd sample. The anodic peak current density was obtained to be about 1.3 times higher on the NiPd-2 sample compared with that for the Pd sample.

• Transactions of the Korean hydrogen and new energy society
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• v.17 no.3
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• pp.241-247
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• 2006

The catalytic performances for CO preferential oxidation in hydrogen-rich fuels were investigated by varying the types of alumina supports, additives excluding platinum, and synthetic methods of impregnation and sol-gel synthesis. The reactions were conducted in the range of $25{\sim}300^{\circ}C$ over Pt, Co, and/or Na impregnated catalysts supported on commercial gamma-alumina, pseudoboehmite, or sol-gel derived xerogels. Catalytic activities were enhanced by cobalt addition due to strong Pt-Co interactions in the bimetallic phase. Additional sodium promoted not only the formation of the Pt-Co bimetallic interphase but also oxygen adsorption capability, giving rise to increase in the CO oxidation rate at lower temperatures. Moreover, chemical interaction between Pt and Co was considerably enhanced by sol-gel synthesis.

• Journal of the Korean Applied Science and Technology
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• v.22 no.4
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• pp.349-354
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• 2005

It is interesting to discover the reaction kinetics of the newly developed molybdenum containing catalysts. The dissociation/adsorption of nitrogen on molybdenum surface is known to be structure sensitive, which is similar to that of nitrogen on iron surface. The rates over molybdenum nitride catalysts are increased with the increase of total pressure. This tendency is the same as that for iron catalyst, but is quite different from that for ruthenium catalyst. The activation energies of the molybdenum nitride catalysts are almost on the same level, although the activity is changed by the addition of the second component. The reaction rate is expressed as a function of the concentration of reactants and products. The surface nature of $CO_3Mo_3N$ is drastically changed by the addition of alkali, changing the main adsorbed species from $NH_2$ to NH on the surface. The strength of $NH_x$ adsorption is found to be changed by alkali dopping.

• Applied Chemistry for Engineering
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• v.7 no.4
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• pp.661-669
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• 1996

Pt-Rh/NaY catalysts with various Pt/Rh ratios were prepared by an ion-exchange method and their characteristics were investigated by $^{129}Xe$-NMR and EXAFS. Both the $^{129}Xe$-NMR and EXAFS data indicate that the surface of PtRh bimetallic clusters was enriched with Rh atoms. The catalytic activities of these catalysts for conversion of CO, HC and $NO_x$ were measured by using simulated automobile engine exhausts under lean, rich and stoichiometric conditions. The Pt-Rh/NaY(Pt/Rh=1) catalyst exhibited the greatest reactive activity among the catalysts used in this study.