Reinforced atomically dispersed Fe-N-C catalysts derived from petroleum asphalt for oxygen reduction reaction

摘要

Massive production of efficient, durable, and low-cost electrocatalysts toward oxygen reduction reaction (ORR) is urgently desired for the development of energy storage and conversion devices. In this study, a facile and cost-effective strategy is proposed for the scalable synthesis of atomically dispersed Fe-N-C derived from petroleum asphalt (Fe-N-C@PA) as a reinforced catalyst for ORR. The Fe-N-C@PA is fabricated through a layer-by-layer cladding template and subsequent pyrolysis method. Intercalating appropriate amount of petroleum asphalt not only improves the graphitic degree to reinforce the atomic Fe-N-x active sites, but also increases mass yield of the catalyst (similar to 220%) compared with the Fe-N-C counterpart. Serving as an ORR electrocatalyst, the optimized Fe-N-C@PA-1:4 provides almost a fourelectron transfer pathway (3.96) and exhibits superior electrocatalytic activity with a half-wave potential (E-1/2) of 0.90 V to the commercial Pt/C catalyst (E-1/2 = 0.86 V), as well as promoted durability and methanol tolerance in alkaline medium. Moreover, the zinc-air battery based on Fe-N-C@PA-1:4 cathode delivers a high power density of 166.7 mW cm(-2). This work may help the massive production of robust atomically dispersed non-noble metal catalysts for ORR and provide a new avenue for the high valueadded utilization of petroleum asphalt. (c) 2020 Elsevier Inc. All rights reserved.