A metal powder for powder metallurgy contains Co as a principal component, Cr at 16 mass % or more and 35 mass % or less, and Si at 0.3 mass % or more and 2.0 mass % or less, wherein when one element selected from Ti, V, Y, Zr, Nb, Hf, and Ta is a first element, and one element selected from the group and having a higher group number in the periodic table than that of the first element or having the same group number in the periodic table as that of the first element and a higher period number than that of the first element is a second element, the first element is at 0.01 mass % or more and 0.5 mass % or less, and the second element is at 0.01 mass % or more and 0.5 mass % or less.

A metal powder for powder metallurgy contains Co as a principal component, Cr at 16 mass % or more and 35 mass % or less, and Si at 0.3 mass % or more and 2.0 mass % or less, wherein when one element selected from Ti, V, Y, Zr, Nb, Hf, and Ta is a first element, and one element selected from the group and having a higher group number in the periodic table than that of the first element or having the same group number in the periodic table as that of the first element and a higher period number than that of the first element is a second element, the first element is at 0.01 mass % or more and 0.5 mass % or less, and the second element is at 0.01 mass % or more and 0.5 mass % or less.

A method for producing coated copper particles having a surface coated with an aliphatic carboxylic acid, wherein the method comprises obtaining a reaction mixture containing copper formate, an amino alcohol, an aliphatic carboxylic acid having an aliphatic group having 5 or more carbon atoms, and a solvent, and subjecting a complex compound formed in the reaction mixture to thermal decomposition treatment to form metal copper, wherein a SP value, which is a difference in SP value between the amino alcohol and the solvent, is 4.2 or more.

A method for producing coated copper particles having a surface coated with an aliphatic carboxylic acid, wherein the method comprises obtaining a reaction mixture containing copper formate, an amino alcohol, an aliphatic carboxylic acid having an aliphatic group having 5 or more carbon atoms, and a solvent, and subjecting a complex compound formed in the reaction mixture to thermal decomposition treatment to form metal copper, wherein a SP value, which is a difference in SP value between the amino alcohol and the solvent, is 4.2 or more.

The present invention describes the use of nanoparticle interfaces to chemically process solid nanomaterials into ones with tailorable core-void-shell architectures. The internal void sizes are proportional to the nanoparticle size, the shell thickness and composition, and can be either symmetric or asymmetric depending on the nature of the interface, each of which is controlled by the process of making.

The present invention describes the use of nanoparticle interfaces to chemically process solid nanomaterials into ones with tailorable core-void-shell architectures. The internal void sizes are proportional to the nanoparticle size, the shell thickness and composition, and can be either symmetric or asymmetric depending on the nature of the interface, each of which is controlled by the process of making.

The present invention describes the use of nanoparticle interfaces to chemically process solid nanomaterials into ones with tailorable core-void-shell architectures. The internal void sizes are proportional to the nanoparticle size, the shell thickness and composition, and can be either symmetric or asymmetric depending on the nature of the interface, each of which is controlled by the process of making.

The present invention describes the use of nanoparticle interfaces to chemically process solid nanomaterials into ones with tailorable core-void-shell architectures. The internal void sizes are proportional to the nanoparticle size, the shell thickness and composition, and can be either symmetric or asymmetric depending on the nature of the interface, each of which is controlled by the process of making.

A method for producing coated copper particles having a surface coated with an aliphatic carboxylic acid, wherein the method comprises obtaining a reaction mixture containing copper formate, an amino alcohol, an aliphatic carboxylic acid having an aliphatic group having 5 or more carbon atoms, and a solvent, and subjecting a complex compound formed in the reaction mixture to thermal decomposition treatment to form metal copper, wherein a SP value, which is a difference in SP value between the amino alcohol and the solvent, is 4.2 or more.

The present disclosure provides a method for synthesizing cobalt-nickel alloy nanoparticles. The method involves dissolving potassium hydroxide in a mixture of ethylene glycol and N, N-dimethylformamide. Cobalt II acetylacetonate and nickel II acetylacetonate are added to the solution. The cobalt II acetylacetonate and nickel II acetylacetonate are stirred into the solution until the cobalt II acetylacetonate and nickel II acetylacetonate have dissolved. The solution is transferred to an autoclave, which in some embodiments is lined with PTFE. The autoclave is heated until the nanoparticles have been synthesized. In some embodiments, the autoclave is heated at 180 C. for 8 hours. The synthesized nanoparticles are collected by centrifuging the product having the synthesized nanoparticles. The nanoparticles are characterized and evaluated for oxygen reduction reaction.