Processes for forming multimetallic alloys and carbon-supported multimetallic alloys

A process for forming carbon-supported PtNiCoRuFe nanoparticles, the process comprising:

• forming a mixture comprising a platinum (Pt) metal source, a nickel (Ni) metal source, a cobalt (Co) metal source, a ruthenium (Ru) metal source, an iron (Fe) metal source, a carbon source, and a solvent, wherein the carbon source comprises carbon nanofiber, mesoporous carbon, carbon nanowire, acetylene black, graphene, a graphene derivative, fullerene, or combinations thereof;
• and
• heating the mixture at a temperature that is from about 80° C. to about 250° C. to form carbon-supported nanoparticles, the carbon-supported nanoparticles comprising:
• a carbon support;
• and
• PtNiCoRuFe single phase alloy nanoparticles chemically bonded to the carbon support, wherein the carbon source comprises graphene, a graphene derivative, or combinations thereof.

A process for forming multimetallic single phase alloy nanoparticles, the process comprising:

• forming a mixture consisting essentially of a platinum (Pt) metal source, a nickel (Ni) metal source, a cobalt (Co) metal source, a ruthenium (Ru) metal source, and a solvent in a reactor, wherein the solvent is selected from the group consisting of a monohydric alcohol, a polyhydric alcohol, or combinations thereof;
• and
• heating the mixture in the reactor at a temperature that is from about 80° C. to about 250° C. while the reactor is pressurized from about 0.12 MPa to about 0.22 MPa to form multimetallic single phase alloy nanoparticles consisting essentially of Pt, Ni, Co, and Ru, wherein:
• the multimetallic single phase alloy nanoparticles are PtNiCoRu nanoparticles;
• and
• the PtNiCoRu nanoparticles consisting essentially of:
• from about 30 atomic % to about 50 atomic % of Pt based on a total atomic % of the Pt, Ni, Co, and Ru in the PtNiCoRu nanoparticles, the total atomic % not to exceed 100 atomic % of the Pt, Ni, Co, and Ru in the PtNiCoRu nanoparticles;
• from about 9 atomic % to about 29 atomic % of Ni based on the total atomic % of the Pt, Ni, Co, and Ru in the PtNiCoRu nanoparticles;
• from about 10 atomic % to about 30 atomic % of Co based on the total atomic % of the Pt, Ni, Co, and Ru in the PtNiCoRu nanoparticles;
• and
• from about 11 atomic % to about 31 atomic % of Ru based on the total atomic % of the Pt, Ni, Co, and Ru in the PtNiCoRu nanoparticles.