Affiliation:
1. Science and Technology on Advanced Ceramic Fibers and Composites Laboratory College of Aerospace Science and Engineering National University of Defense Technology 109 De Ya Road Changsha Hunan 410073 China
2. Department of Aviation Oil and Material Air Force Logistics Academy 72 Xi Ge Road Xuzhou Jiangsu 221000 China
3. College of Chemistry and Molecular Sciences Wuhan University 299 Ba Yi Road Wuhan Hubei 300720 China
4. Department of Chemistry Southern University of Science and Technology 1088 Xueyuan Road Shenzhen 518055 China
Abstract
AbstractFe─N─C is the most promising alternative to platinum‐based catalysts to lower the cost of proton‐exchange‐membrane fuel cell (PEMFC). However, the deficient durability of Fe─N─C has hindered their application. Herein, a TiN‐doped Fe─N─C (Fe─N─C/TiN) is elaborately synthesized via the sol–gel method for the oxygen‐reduction reaction (ORR) in PEMFC. The interpenetrating network composed by Fe─N─C and TiN can simultaneously eliminate the free radical intermediates while maintaining the high ORR activity. As a result, the H2O2 yields of Fe─N─C/TiN are suppressed below 4%, ≈4 times lower than the Fe─N─C, and the half‐wave potential only lost 15 mV after 30 kilo‐cycle accelerated durability test (ADT). In a H2─O2 fuel cell assembled with Fe─N─C/TiN, it presents 980 mA cm−2 current density at 0.6 V, 880 mW cm−2 peak power density, and only 17 mV voltage loss at 0.80 A cm−2 after 10 kilo‐cycle ADT. The experiment and calculation results prove that the TiN has a strong adsorption interaction for the free radical intermediates (such as *OH, *OOH, etc.), and the radicals are scavenged subsequently. The rational integration of Fe single‐atom, TiN radical scavenger, and highly porous network adequately utilize the intrinsic advantages of composite structure, enabling a durable and active Pt‐metal‐free catalyst for PEMFC.