Abstract: | Metal‐free N‐doped porous carbon has great potential as a catalyst for hydrazine oxidation in direct hydrazine fuel cells (DHFCs). However, previous studies have reported only half‐cell characterization, and the effect of the pore size distribution has not been intensively investigated. Herein, we report the synthesis of highly active, metal‐free N‐doped carbon (NDC) by controlling the pore size distribution, and for the first time, the effect of the pore size distribution on the anode performance in a DHFC is investigated. As a result, tree‐bark‐shaped NDC with meso /macroporous (>10 nm) structures exhibit a remarkable power density of 127.5 mW cm−2 in a DHFC. |