Template‐free synthesis of novel hollow carbon nanospheres with dual active sites as catalyst for fuel cell cathode to improve oxygen reduction reaction performances

Abstract

Summary A new template‐free controlled method is reported herein to prepare the novel hollow carbon nanospheres with dual active sites of FeN4 and FeC3 by in situ growth reaction on graphene nanosheets, labeled as HCN‐FNFCG. As‐prepared HCN‐FNFCG nanomaterials possess hierarchically porous FeN4/FeC3 shells with structures of microporous, mesoporous, and macroporous properties. Moreover, the hierarchically porous HCN‐FNFCG nanomaterials with dual active sites of FeN4 and FeC3 have not been reported before. The HCN‐FNFCG nanomaterials, as oxygen reduction reaction (ORR) catalysts, are first studied systematically toward cathodic ORR of fuel cell. The measurements have illustrated that HCN‐FNFCG‐650 has the best ORR performances among these HCN‐FNFCG nanomaterials studied. The onset potential of HCN‐FNFCG‐650 has reached 1.095 V in alkaline electrolyte, and its maximum current density is 6.48 mA cm−2. Additionally, the HCN‐FNFCG‐650 has also displayed small electrochemical impedance, its Tafel‐slope value is 44.25 mV dec−1, much lower than that of the 20% Pt/C (69.57 mV dec−1). And its value of current density is still maintained 92.83% of the initial value after 9000‐second continuous tests. High tolerance against methanol crossover is also exhibited for HCN‐FNFCG‐650. This novel method of template‐free synthesis can provide a promising strategy for preparing hollow nanospheres with hierarchically porous shells. And it can be used to design ORR electrocatalysts, electrode materials, or other applications.

H 2 ‐induced thermal treatment significantly influences the development of a high performance low‐platinum core‐shell PtNi/C alloyed oxygen reduction catalyst

“…5,6 However, the oxygen reduction reaction (ORR) at cathode is more complicated and pivotal in achieving the better fuel cell performance, so ORR catalysts are decisive in the development and widespread commercialization of PEMFCs. [7][8][9] Fabricating the highly active, low-platinum and durable ORR catalyst is one of the most effective way for the improvement of fuel cells performance. 10,11 Continuously, platinum blossoms out to be the most practical catalyst for ORR catalysis in the real application of PEMFC.…”

“…As an efficient energy conversion devices, the operating principle of PEMFC is typically made up of two fundamental electrochemical processes on each side of the polymer electrolyte membrane electrodes . However, the oxygen reduction reaction (ORR) at cathode is more complicated and pivotal in achieving the better fuel cell performance, so ORR catalysts are decisive in the development and widespread commercialization of PEMFCs . Fabricating the highly active, low‐platinum and durable ORR catalyst is one of the most effective way for the improvement of fuel cells performance …”

Microwave‐assisted synthesis of cobalt‐polyoxometalate @carbon black nanocomposites and their electrocatalytic ability toward oxygen reduction reaction

“…[26][27][28][29][30] In a few reports, POMs with carbonaceous materials have been shown to be effective for ORR [31][32][33][34][35] ; while in others, several new noble-metal free composites have been studied. 6,[36][37][38][39][40][41][42] However, still the use of POM based composites as a noble-metal free electrocatalysts particularly for ORR needs to be explored.…”

A novel predicting method on degree of catalytic reaction in fuel cells

“…At present, FCs are hard to industrialize mainly because of their poor performance, short life, and high cost 6 . Research on the catalyst‐layer in FCs would play a significant role in solving the abovementioned problems 7‐9 . The maximum output power of the FCs can be increased by optimizing the catalytic reaction 10 .…”