A neural-network-like catalyst structure for the oxygen reduction reaction: carbon nanotube bridged hollow PtCo alloy nanoparticles in a MOF-like matrix for energy technologies
The rational design of a catalytic layer in a membrane-electrode assembly is the key to achieve high performances from proton exchange membrane fuel cells (PEMFCs). Herein, inspired by the neural-network structure of the brain, we constructed a bionic catalytic network for the oxygen reduction reaction (ORR), via setting up Pt-organic ligands–Co2+–organic ligands–Pt connections and then thermally transforming them into a metal-organic-framework (MOF)-like matrix in which hollow PtCo alloy nanoparticles (NPs) with an average particle size of 4.4 nm are bridged together by carbon nanotubes (PtCo@CNTs-MOF). The bionic catalytic network provides highly efficient linkages of various species-transport channels to active sites; as a result, an order of magnitude improvement is achieved in mass transfer efficiency as compared to the traditional Pt/C catalytic layer. Besides, the hollow PtCo alloy derived from Pt NPs shows a high initial mass activity of 852 mA mgPt−1 @ 0.90 V and an undetectable decay in an accelerated aging test. Accordingly, a remarkable Pt utilization efficiency of 58 mgPt kW−1 in the fuel cell cathode and 98 mgPt kW−1 in both the anode and cathode was eventually achieved, respectively. The latter is almost 3 times higher than that of the traditional catalytic layer. Moreover, no decay was detected during continuous operation at 1 A cm−2 for 130 hours from the bionic catalytic network based fuel cell. This strategy offers a new concept for designing an ultra-low Pt loading yet highly active and durable catalytic layer for fuel cell applications and beyond.
Funding
International Cooperation Project of National Natural Science Foundation of China (Grant No. 21761162015)
National Natural Science Foundation of China (Grant No. 21706019, 21436003, 21573029 and 21776024)
EPSRC (EP/I013229/1)
Royal Society and the Newton Fund (NAF\R1\191294)
History
School
- Aeronautical, Automotive, Chemical and Materials Engineering
Department
- Chemical Engineering
Published in
Journal of Materials Chemistry AVolume
7Issue
34Pages
19786 - 19792Publisher
Royal Society of Chemistry (RSC)Version
- AM (Accepted Manuscript)
Rights holder
© The Royal Society of ChemistryPublisher statement
This paper was accepted for publication in the journal Journal of Materials Chemistry A and the definitive published version is available at https://doi.org/10.1039/c9ta06712d.Acceptance date
2019-07-31Publication date
2019-08-15Copyright date
2019ISSN
2050-7488eISSN
2050-7496Language
- en