The Peters Projection is not supported. ArcGIS only supports map projections that don't require a license.
The Peters Projection is designed to minimizes distortion of area for all the countries of the world. See the Related Information section of this document for more information.
For a similar looking map projection that is supported, try Cylindrical Equal Area with the standard parallel set to 45 degrees. Other map projections that minimize areal distortion include Robinson and Winkel Tripel.