Methods for manufacturing carbon nanostructures include: 1) forming a plurality of catalytic templating particles using a plurality of dispersing agent molecules; 2) forming an intermediate carbon nanostructure by polymerizing a carbon precursor in the presence of the plurality of templating nanoparticles; 3) carbonizing the intermediate carbon nanostructure to form a composite nanostructure; and 4) removing the templating nanoparticles from the composite nanostructure to yield the carbon nanostructures. The carbon nanostructures are well-suited for use as a catalyst support. The carbon nanostructures exhibit high surface area, high porosity, and high graphitization. Carbon nanostructures according to the invention can be used as a substitute for more expensive and likely more fragile carbon nanotubes.