• Proceedings of the Korean Vacuum Society Conference
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• 1992.02a
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• pp.19-20
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• 1992

• Journal of the Korean Chemical Society
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• v.22 no.6
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• pp.370-379
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• 1978

The specific rate constants for the oxidation reactions of carbon monoxide on a unit catalytic surface area were measured. The catalysts used were NiO made from $Ni(NO_3)_2,\;and\;Ni(OH)_2$, and Mn$O_2$ made from Mn$(NO_3)_2$. At low pressure the reaction rate was found to be of second order and the activation energies were 12 kcal/mole (on NiO made from Ni$(NO_3)_2$, 17 kcal/mole (on NiO made from Ni$(OH)_2)$) and 18 kcal/mole (on Mn$O_2$). Plausible reaction mechanisms were proposed from the experimentally determined reaction orders.

• Korean Chemical Engineering Research
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• v.49 no.6
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• pp.720-725
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• 2011

Gold catalysts supported on metal-oxides were prepared by co-precipitation using the various metal nitrates and chloroauric acid as precursors, and effect of water addition on the catalytic activity in CO oxidation was investigated. Among the various supported gold catalysts, Au/$Co_{3}O_{4}$ and Au/ZnO catalysts showed the excellent activity for CO oxidation. Water in the reactant gas had a negative effect on the oxidation activity over Au/$Co_{3}O_{4}$ catalysts and a positive effect on that over Au/ZnO, which means the activity depends strongly on the nature of support. It was also confirmed that no significant change in the particle size of gold was observed after reaction both in dry and wet conditions. This fact suggested that the deactivated catalyst due to a carbonate species could be regenerated by water addition in the reactant gas.

• Applied Chemistry for Engineering
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• v.19 no.2
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• pp.157-160
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• 2008

The generation of high-purity hydrogen from hydrocarbon fuels is essential for efficient operation of fuel cell. In general, most feasible strategies to generate hydrogen from hydrocarbon fuels consist of a reforming step to generate a mixture of $H_2$, CO, $CO_2$ and $H_2O$ (steam) followed by water gas shift (WGS) and CO clean-up steps. The WGS reaction that shifts CO to $CO_2$ and simultaneously produces another mole of $H_2$ was carried out in a two-stage catalytic conversion process involving a high temperature shift (HTS) and a low temperature shift (LTS). In a typical operation, gas emerges from the reformer is taken through a high temperature shift catalyst to reduce the CO concentration to about 3~5%. The HTS reactor was designed and tested in this study to produce hydrogen-rich gas with CO to a range of 2~4%. The iron based catalysts (G-3C) was used for the HTS to convert the most of CO in the effluent from the partial oxidation (POX) to $H_2$ and $CO_2$ at a relatively high rate. Parametric screening studies were carried out for variations of the following variables: reaction temperature, steam flow rate, components ratio ($H_2/CO$), and reforming gas flow rate.

• Clean Technology
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• v.8 no.1
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• pp.53-59
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• 2002

$Cu-CeO_2$ catalysts were prepared by co-precipitation and liquid phase oxidation (CP-LPO) and the prepared catalysts were examined as selective oxidation of carbon monoxide catalysts for the application of fuel cell vehicles. The prepared $Cu-CeO_2$ catalysts showed high reaction activity, but it was hard to find the correlation between the amount of Cu loaded and the reaction activities. As increase of the amount of Cu loaded, the micro pore structure of the catalyst was changed. It is due to the formation of solid solution between Cu and $CeO_2$. During pretreatment, the catalyst formed the solid-solution of Cu-Ce-O, resulting in the improvement of catalytic activity.

• Korean Chemical Engineering Research
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• v.49 no.1
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• pp.1-9
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• 2011

Platinum catalysts were prepared by impregnating platinum precursor on titania-, vanadia-, zirconia- and ceria-incorporated silicas followed by hydrogen peroxide treatment. The effects of the oxide incorporation and the hydrogen peroxide treatment in the preparation of the platinum catalysts on their platinum dispersion and catalytic activity in carbon monoxide oxidation were investigated. XRD, TEM, EXAFS, XPS and carbon monoxide chemisorption studies confirmed the high dispersion of platinum even on silica by the oxide incorporation and hydrogen peroxide treatment. However, the type of oxides incorporated on silica caused considerable variances in the adsorption and the catalytic activity in the oxidation of carbon monoxide on them. The incorporation of titania, zirconia and ceria on silica and further hydrogen peroxide treatment enhanced the platinum dispersion, resulting in the improved catalytic activities. Among the catalysts supported on the oxide-incorporated silicas, the platinum catalyst supported on zirconia-incorporated silica exhibited the highest activity because of the highest platinum dispersion due to the formation of Pt-O-Zr bonds.

• Clean Technology
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• v.13 no.1 s.36
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• pp.54-63
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• 2007

Even traces of CO in the hydrogen-rich feed gas to proton exchange membrane fuel cells (PEMFC) poison the platinum anode electrode and dramatically decrease the power output. In this work, a variety of catalytic materials consisting of $Cu/Ce_xZr_{1-x}O_2$, (x = 0.0-1.0) were synthesised, characterized and tested for CO oxidation and preferential oxidation of CO (PROX). These catalysts prepared by hydrothermal and deposition-precipitation methods. The catalysts were characterized by XRD, XRF, SEM, BET, $N_2O$ titration and oxygen storage capacity (OSC) measurement. The effects of composition of the support and degree of excess oxygen were investigated fur activity and $CO_2$ selectivity with different temperatures. The composition of the support markedly influenced the PROX activity. Among the various $Cu/Ce_xZr_{1-x}O_2$ catalysts having different composition, $Cu/Ce_{0.9}Zr_{0.1}O_2$ and $Cu/Ce_{0.7}Zr_{0.3}O_2$ showed the highest activities (>99%) and selectivities (ca.50%) in the temperature range of $150{\sim}160^{\circ}C$. It was found that by using of $Ce_xZr_{1-x}O_2$ mixed oxide support which possesses a high oxygen storage capacity, oxidation-reduction activity of Cu-based catalyst was improved, which resulted in the increase of catalytic activity and selectivity of CO oxidation in excess $H_2$ environments.

• Korean Chemical Engineering Research
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• v.51 no.4
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• pp.455-459
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• 2013

The fuel processor for the portable fuel cell includes multi-step processes consisting of hydrogen generator, heat generator and several CO clean-up stages. One of requirements of the fuel processor for portable fuel cell system is a rapid start-up time. Especially, the warm-up time for WGS reactor is crucial factors for total start-up time. In this paper, active heating protocol, which is the heating protocol of WGS reactor supplied by the oxidation of CO rich reformate in the initial stage, is used for a rapid start-up. The air stream fed to the inlet of WGS reactor rapidly oxidize the CO rich reformate in the WGS reactor. Therefore, CO concentration in reformate quickly stabilized at the desired concentration without CO surges.

• Applied Chemistry for Engineering
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• v.30 no.2
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• pp.151-154
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• 2019

We report the effective fabrication processes for more practical monolith catalysts consisting of washcoated alumina on a cordierite honeycomb monolith (CHM) and iron oxides nanoparticles in the alumina prepared by a simple dry coating method. It is confirmed that iron oxide nanoparticles were well deposited into the mesopore of washcoated alumina which is formed on the corner wall of honeycomb channel, and the effect of annealing temperature was evaluated for carbon monoxide oxidation catalysts. $Fe_2O_3/{\gamma}-Al_2O_3/CHM$ catalysts annealed at $350^{\circ}C$ exhibited the most enhanced catalytic activity, 100% conversion efficiency at more than $200^{\circ}C$ operating temperature.

• Applied Chemistry for Engineering
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• v.5 no.2
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• pp.189-198
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• 1994

The adsorptive behaviors of carbon monoxide and methanol over $V_2O_5$catalyst were studied by means of thermal desorptlon spectroscopy (TDS) under ultrahigh vacuum conditions. Carbon monoxide adsorbed on oxygen-deficient V sites as well as on V=O groups of the $V_2O_5$ surface. CO adsorbed on the V sites desorbed at 380 K while CO adsorbed on the V=O groups formed carbonate species with surface oxygen of $V_2O_5$ and desorbed as $CO_2$ resulting in the reduction of the surface of she $V_2O_5$catalyst. The amount of CO adsorbed in the form of carbonate species increased by both the pre- and post-adsorbed oxygen. The adsorptive behavior of methanol over the catalyst was studied by thermal desorption experiments of $CH_3OH$, HCHO, CO, and $H_2$ upon methanol adsorption at 298 K. The results showed that methanol was adsorbed dissociatively on the $V_2O_5$catalyst as methoxy and hydroxyl groups at 298K.