Processes for forming carbon-supported platinum nanocrystals of different morphologies

A process for forming platinum nanocrystals of a selected morphology on a carbon support, the process comprising:

• forming a mixture comprising a platinum metal source, a carbon source, an acid, and a solvent;
• and
• heating the mixture at a temperature within a single temperature range inclusive for a selected period of time to form a carbon-supported platinum nanocatalyst, wherein:
• the carbon-supported platinum nanocatalyst comprises platinum nanocrystals chemically bonded to a carbon support;
• and
• the platinum nanocrystals are in the form of nanocubes or irregular nanospheres.

A process for forming platinum nanocrystals on a carbon support, the process comprising:

• reacting, under reaction conditions, a mixture comprising a platinum metal source, a carbon source, an acid, and a solvent to form a carbon-supported platinum nanocatalyst, wherein:
• the carbon-supported platinum nanocatalyst comprises platinum tetrahedra nanocrystals chemically bonded to the carbon support;
• the carbon source comprises a structure having graphitic bonds partially incorporating oxygen atoms;
• and
• the reaction conditions comprise:
• heating the mixture at a first temperature or first temperature range for a first period;
• then
• heating the mixture at a second temperature or second temperature range for a second period;
• and then
• heating the mixture at a third temperature or third temperature range for a third period, wherein at least two of the first temperature or range, the second temperature or range, and the third temperature or range are different.