Effect of Palladium and Nickel on the Temperature Programmed Reduction of Metal Oxides and Metal Oxide Layers

Kim, Jong Pal 한국화학공학회 2004 Korean Journal of Chemical Engineering Vol.21 No.2

A new binary oxide support was suggested as being useful in many commercial reactions. Our study was focused on the reduction effect of metal oxide layer on alumina during reaction. Hence temperature programmed reduction of both bulk metal oxide and metal oxide layer on alumina was studied first and the effect of palladium and nickel on the reduction of the oxide support was also investigated. Vanadium oxide was mainly studied and niobium oxide, tantalum oxide, titanium oxide and zirconium oxide were also compared. Some metal oxides were reduced in a hydrogen stream at elevated temperature. In these cases both the bulk metal oxide and metal oxide layer were reduced. A tiny amount of palladium or nickel affected the reduction by decreasing the reduction temperature. The decrease of the reduction temperature was explained by means of increased adsorption of hydrogen on the transition metal and ability of the metal to spillover of the hydrogen to the oxides.

Effect of Palladium and Nickel on the Temperature Programmed Reduction of Metal Oxides and Metal Oxide Layers

김종팔 한국화학공학회 2004 Korean Journal of Chemical Engineering Vol.21 No.2

A new binary oxide support was suggested as being useful in many commercial reactions. Our study wasfocused on the reduction effect of metal oxide layer on alumina during reaction. Hence temperature programmedreduction of both bulk metal oxide and metal oxide layer on alumina was studied first and the effect of palladium andnickel on the reduction of the oxide support was also investigated. Vanadium oxide was mainly studied and niobiumoxide, tantalum oxide, titanium oxide and zirconium oxide were also compared. Some metal oxides were reduced ina hydrogen stream at elevated temperature. In these cases both the bulk metal oxide and metal oxide layer werereduced. A tiny amount of palladium or nickel afected the reduction by decreasing the reduction temperature. Thedecrease of the reduction temperature was explained by means of increased adsorption of hydrogen on the transitionmetal and ability of the metal to spillover of the hydrogen to the oxides.

코발트 산화물과 지지체 표면의 코발트 산화물의 환원에 니켈과 팔라듐 첨가의 효과

김종팔,이광현 동의대학교 산업기술개발연구소 2006 産業技術硏究誌 Vol.20 No.-

A binary oxide support was suggested as being useful in many commercial reactions. This study was focused on the reduction effect of metal oxide on alumina surface. Hence temperature programmed reduction of both bulk metal oxide and metal oxide on alumina surface was studied first and effect of nickel and palladium on the reduction of the metal oxides was also investigated. Cobalt oxide was studied and it was reduced in a hydrogen stream at elevated temperature. In these cases both the bulk metal oxide and metal oxide on surface were reduced. A tiny amount of palladium or nickel affected the reduction by decreasing the reduction temperature. The decrease of the reduction temperature was explained by means of increased adsorption of hydrogen on the transition metal and ability of the metal to spillover of the hydrogen to the oxides.

Tuning of electrical properties in correlated transition metal oxides for electronics

손준우 한국공업화학회 2016 한국공업화학회 연구논문 초록집 Vol.2016 No.0

Correlated transition metal oxides have attracted considerable attention due to a remarkable array of functionalities that stem from the strong correlations between the localized transition metal valence d electrons. One of the representative functionalities in transition metal oxides includes abrupt phase transition under external stimuli, e.g. metal-insulator transition, in correlated electron systems. The uniques property can be applicable to the electronic devices for steep electronic switch, such as the logic and memory devices with high on/off ratio, the selector devices for 3D cross point memory. In this presentation, I will represent our recent result to realize unconventional electronic devices, such as the steep selector devices and synaptic analog devices for neuromorphic application, using correlated oxides, such as NbO2, NdNiO3 etc.

Transition metal (Fe, Co, Ni, and Mn) oxides for oxygen reduction and evolution bifunctional catalysts in alkaline media

Osgood, Hannah,Devaguptapu, Surya V.,Xu, Hui,Cho, Jaephil,Wu, Gang Elsevier 2016 Nano Today Vol.11 No.5

<P><B>Abstract</B></P> <P>In recent years, a large amount of focus has been given to the development of alternative energy sources that are clean and efficient; among these, electrochemical energy holds potential for its compatibility with solar and wind energy, as well as their applications in fuel cells, and metal-air batteries, and water electrolyzers. However, these technologies require the use of highly active and stable catalysts to make these applications feasible. Current catalysts consist of precious metals such as platinum and iridium, which are expensive and block common access to electrochemical energy. Transition metals, and their oxides, serve as a promising alternative to these precious metals. due to their intrinsic activity and sufficient stability in oxidative electrochemical environments. Among wide range of these metals, cobalt, manganese, nickel, and iron, have been extensively explored as bifunctional catalysts, capable of simultaneously catalyzing oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) for energy storage and conversion. Not only do they show innate electrochemical capabilities, but their structural diversity, as well as their ability to be mixed, doped, and combined with other materials such as graphene, make transition metal oxides a highly attractive subject in electrochemical and materials research. This review serves to summarize the research currently available concerning transition metal oxides, and their applications as a bifunctional catalyst for the utilized fuel cells and rechargeable metal-air batteris in alkaline media. Particularly, oxide synthesis and their structural properties are related to their electrochemical abilities, along with their behavior when introduced to other catalytic materials and dopants.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Review transition metal oxide catalyst for electrochemical energy and conversion via O<SUB>2</SUB> electrocatalysis. </LI> <LI> Provide an overview for cobalt, manganese, nickel, and iron oxide catalysts in terms of their synthesis, structure/morphology, and catalytic activity. </LI> <LI> Focus on elucidation of synthesis–structure–activity correlations for metal oxide nanocomposite catalysts. </LI> <LI> Discuss future oxide catalyst approaches to addressing challenges for ORR and OER catalysis. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Agent-free synthesis of graphene oxide/transition metal oxide composites and its application for hydrogen storage

Hong, W.G.,Kim, B.H.,Lee, S.M.,Yu, H.Y.,Yun, Y.J.,Jun, Y.,Lee, J.B.,Kim, H.J. Pergamon Press ; Elsevier Science Ltd 2012 International journal of hydrogen energy Vol.37 No.9

Graphene oxide (GO) wrapped transition metal oxide composite materials were synthesized by a very simple route without any additional agents and the hydrogen adsorption properties of the materials were investigated. The morphologies of GO/V<SUB>2</SUB>O<SUB>5</SUB> and GO/TiO<SUB>2</SUB> were examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results show that single- or few-layered GO sheets wrapped throughout the V<SUB>2</SUB>O<SUB>5</SUB> and TiO<SUB>2</SUB> particles. According to X-ray photoelectron spectroscopy (XPS), the C-OH species of GO and the surface-adsorbed oxygen of the transition metal oxide bond together via a dehydration reaction. The wrapping phenomenon of GO causes the enhancement of hydrogen storage capacity at liquid nitrogen temperature (77 K) compared with those of the pristine transition metal oxides and GO. The enhancement of hydrogen storage capacity of GO-wrapped transition metal oxide composite materials results from the existence of interspaces between the transition metal oxide particles and the thin GO layers.

나트륨 이온 배터리의 성능 개선을 위한 전이 금속 기반 음극 소재 개발 동향

김민기,박정호 대한전기학회 2023 전기학회논문지 Vol.72 No.3

While lithium-ion battery (LIB) is limited in its large-scale energy storage usage due to the scarcity of lithium resource, sodium-ion battery (SIB) is a promising alternative to LIB in the field of large-scale energy storage since sodium is abundant resource. When the chemical reaction of SIB is converted into electrical energy, sodium ions are inserted more slowly because the radius of the sodium ion is larger than lithium ion, which causes a decrease in capacitance, deforms the structure in the electrode, and deteriorates the electrochemical performance. To solve this problem, the development of SIB anode material with high capacity and structural stability is investigated. Transition metal oxide (TMO) and transition metal dichalcogenide (TMD) are considered to be promising anode materials for SIB since they have high capacity and high energy density. The review of the edvelopment trend of TMO-based anode material for SID performance improvement will lead us to realize better SIB.

Oxidised plasma-sprayed transition metal – Reusable supported catalysts for organic waste treatment

Subhasree Bhaskar,Steven J. Matthews,Mark I Jones,Saeid Baroutian 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.113 No.-

Transition metals were plasma-sprayed onto stainless-steel substrates and further oxidised to form a surface layer of the metal oxides. Catalytic wet oxidation of glucose, a model compound for organic waste was carried out at temperature range of 150–170 °C for 60 min. Rietveld patterns showed evidence of metal oxides in the oxidised coatings of MoO3, Co3O4, CuO and CuNiIn oxide. The SEM cross-sections reveal two-layered coatings for MoO3, Co3O4 and CuO. Highest COD reduction was obtained by Co3O4 after 60 min at 160 °C for the low-oxygen screening trials. Initial screening trials detected a high concentration of metallic Mo, Co and Cu by ICP-MS. The re-oxidised MoO3 catalysts yielded the highest concentration of acetic acid (96 mg L−1) post 60 min of CWO reaction at 170 °C using 40 bar O2. The leaching of Mo metal with spallation of the top oxide layer was confirmed with the reuse trials. On contrary, CuNiIn oxide showed minimum amounts of leached Cu, Ni, and In metals into the reaction media, with the catalyst producing 67 mg L−1 of acetic acid at 170 °C using 40 bar O2. Therefore, CuNiIn oxide was selected as the best oxidised transition metal catalyst for CWO of glucose.

The Preparation of Non-aqueous Supercapacitors with Lithium Transition-Metal Oxide/Activated Carbon Composite Positive Electrodes

Kim, Kyoung-Ho,Kim, Min-Soo,Yeu, Tae-Whan Korean Chemical Society 2010 Bulletin of the Korean Chemical Society Vol.31 No.11

In order to increase the specific capacitance and energy density of supercapacitors, non-aqueous supercapacitors were prepared using lithium transition-metal oxides and activated carbons as active materials. The electrochemical properties were analyzed in terms of the content of lithium transition-metal oxides. The results of cyclic voltammetry and AC-impedance analyses showed that the pseudocapacitance may stem from the synergistic contributions of capacitive and faradic effects; the former is due to the electric double layer which is prepared in the interface of activated carbon and organic electrolyte, and the latter is due to the intercalation of lithium ($Li^+$) ions. The specific capacitance and energy density of a supercapacitor improved as the lithium transition-metal oxides content increased, showing 60% increase compared to those of supercapacitor using a pure activated carbon positive electrode.

The Preparation of Non-aqueous Supercapacitors with Lithium Transition-Metal Oxide/Activated Carbon Composite Positive Electrodes

Kyoungho Kim,김민수,Taewhan Yeu 대한화학회 2010 Bulletin of the Korean Chemical Society Vol.31 No.11

In order to increase the specific capacitance and energy density of supercapacitors, non-aqueous supercapacitors were prepared using lithium transition-metal oxides and activated carbons as active materials. The electrochemical properties were analyzed in terms of the content of lithium transition-metal oxides. The results of cyclic voltammetry and ACimpedance analyses showed that the pseudocapacitance may stem from the synergistic contributions of capacitive and faradic effects; the former is due to the electric double layer which is prepared in the interface of activated carbon and organic electrolyte, and the latter is due to the intercalation of lithium (Li+) ions. The specific capacitance and energy density of a supercapacitor improved as the lithium transition-metal oxides content increased, showing 60% increase compared to those of supercapacitor using a pure activated carbon positive electrode.