摘要:
A catalyst is disclosed herein. The catalyst includes a reducible oxide support and at least one noble metal fixed on the reducible oxide support. The noble metal(s) is loaded on the support at a substantially constant temperature and pH.
摘要:
A non-oxide, transition metal based ceramic material has the general formula A.sub.y M.sub.2 Z.sub.x, wherein A is a group IA element, M is a transition metal and Z is selected from the group consisting of N, C, B, Si, and combinations thereof, and wherein x.ltoreq.2 and y.ltoreq.6-x. In these materials, the group IA element occupies interstitial sites in the metallic lattice, and may be readily inserted into or released therefrom. The materials may be used as catalysts and as electrodes. Also disclosed herein are methods for the fabrication of the materials.
摘要:
Mesoporous desigels are fabricated as nitrides, carbides, borides, and silicides of metals, particularly transition metals, and most particularly early transition metals. The desigels are prepared by forming a gel of a metallic compound, and removing solvent from the gel. In some instances, the thus produced desigel may be further reacted to change its composition, while preserving its mesoporous structure. The materials are particularly suited as electrodes for capacitors, including ultracapacitors, and for batteries.
摘要:
High surface area electrodes for use in electrical and electrochemical energy storage and conversion devices comprise conductive transition metal nitrides, carbides, borides or combinations thereof where the metal is molybdenum or tungsten. Disclosed is a method of manufacturing such electrodes by forming or depositing a layer of metal oxide, then exposing the metal oxide layer at elevated temperature to a source of nitrogen, carbon or boron in a chemically reducing environment to form the desired metal nitride, carbide or boride film. Also disclosed is an ultracapacitor comprised of the new high surface area electrodes having a specific capacitance of 100 mF/cm.sup.2 and an energy density of 100 mJ/cm.sup.3 with improved conductivity and chemical stability when compared to currently available electrodes.
摘要翻译:用于电和电化学能量存储和转换装置的高表面积电极包括金属为钼或钨的导电过渡金属氮化物,碳化物,硼化物或其组合。 公开了一种通过形成或沉积一层金属氧化物来制造这种电极的方法,然后在化学还原环境中将金属氧化物层在升高的温度下暴露于氮,碳或硼源,以形成所需的金属氮化物,碳化物或 硼化物膜。 还公开了一种超级电容器,其包括具有100mF / cm 2的比电容的新的高表面积电极和100mJ / cm 3的能量密度,与当前可用的电极相比具有改善的导电性和化学稳定性。
摘要:
A catalyst composition contains an active metal on a support including a high surface area substrate and an interstitial compound, for example molybdenum carbide. Pt—Mo2C/Al2O3 catalysts are described. The catalyst systems and compositions are useful for carrying out reactions generally related to the water gas shift reaction (WGS) and to the Fischer-Tropsch Synthesis (FTS) process.
摘要:
A catalyst comprises an electrically conductive ceramic substrate having at least one noble metal supported thereupon. The substrate may be a transition metal based ceramic such as a carbide, nitride, boride, or silicide of a transition metal, and the noble metal may comprise a mixture of noble metals. The substrate may comprise a high surface area ceramic. Also disclosed are fuel cells incorporating the catalysts.
摘要:
A facile synthesis of the precursor, Cp.sub.2 Mo.sub.2 (.mu.-S).sub.2 (.mu.-SH).sub.2, to novel heterobimetallic cluster compositions (e.g., Cp.sub.2 Mo.sub.2 Fe.sub.2 (.mu.-S).sub.2 (CO).sub.8 ; Cp.sub.2 Mo.sub.2 Ni.sub.2 (.mu..sub.3 -S).sub.4 (CO).sub.2 ; Cp.sub.2 Mo.sub.2 Co.sub.2 (.mu..sub.3 -S).sub.2 (.mu..sub.4 -S)(CO).sub.4 ; Cp.sub.2 Mo.sub.2 Fe.sub.2 (.mu..sub.3 -S).sub.4 (CO).sub.6 and Cp.sub.4 Mo.sub.2 Ni.sub.2 S.sub.4 and the subsequent synthesis and use of the heterobimetallic cluster compositions as highly active and selective catalysts for the hydrogenation of carbon monoxide. Such heterobimetallic cluster catalysts supported on alumina exhibit extraordinary activity and selectivity with respect to the formation of ethane without concommitant formation of C.sub.3, C.sub.4 and heavier hydrocarbons. The catalysts are contemplated as being useful for syngas conversion even in the presence of several ppm of H.sub.2 S or the like in the feedstream.
摘要:
In accordance with an embodiment of the disclosure, an asymmetric supercapacitor includes a first active material with a high hydrogen over-potential and a second active material with a high oxygen over-potential. The first active material is based on a nitride, an oxynitride, a carbide, an oxycarbide, a boride, or an oxyboride of a metal selected from Groups III, IV, V, VI, and VII of the Periodic Table.
摘要:
In accordance with an embodiment of the disclosure, a method of making a supercapacitor includes impregnating a foam electrode substrate with an active material precursor, wherein the foam electrode substrate includes a plurality of pores and the active material precursor is dispersed into the pores. The method further includes reacting the active material precursor infiltrated foam substrate with a reductant under conditions sufficient to convert the active material precursor to an active material, wherein the active material is based on a nitride, an oxynitride, a carbide, or an oxycarbide of a metal selected from Groups III, IV, V, VI, or VII of the Periodic Table.
摘要:
In accordance with an embodiment of the disclosure, an asymmetric supercapacitor includes a first active material with a high hydrogen over-potential and a second active material with a high oxygen over-potential. The first active material is based on a nitride, an oxynitride, a carbide, an oxycarbide, a boride, or an oxyboride of a metal selected from Groups III, IV, V, VI, and VII of the Periodic Table.