Platinum-deposited titanium nitride (Pt/TiN) nanoparticle aggregates with high porosities were successfully prepared via a self-assembly-assisted spray pyrolysis method. The addition of formic acid (HCOOH) had a significant influence on the process, promoting the simultaneous formation of metallic Pt and reduction on the surface of the TiN support material. Complete reduction of the Pt/TiN nanoparticle aggregates improved the catalytic activity. The electrochemical surface area (ECSA) of Pt/TiN with HCOOH (Pt/TiNw/HCOOH) was 87.15 m(2)/g-Pt, which was higher than that of Pt/TiN without HCOOH (Pt/TiNw/o-HCOOH). The catalytic durability of Pt/TiNw/HCOOH was twice that of Pt/TiNw/o-HCOOH. An effective strategy for obtaining carbon-free catalysts with high activities and durabilities was identified. (c) 2013 American Institute of Chemical Engineers AIChE J, 59: 2753-2760, 2013