Highly stable and ordered intermetallic PtCo alloy catalyst supported on graphitized carbon containing Co@CN for oxygen reduction reaction

2020 ◽  
Vol 8 (38) ◽  
pp. 19833-19842
Author(s):  
Won Suk Jung ◽  
Woong Hee Lee ◽  
Hyung-Suk Oh ◽  
Branko N. Popov

Ordered intermetallic PtCo synthesized from N-doped graphitic carbon-containing Co presents the high durability with low Pt loading after 30 000 load-simulated cycles in proton exchange membrane fuel cells.

2021 ◽  
Author(s):  
Minhua Shao ◽  
Fei Xiao ◽  
Qi Wang ◽  
Gui-Liang Xu ◽  
Xueping Qin ◽  
...  

Abstract Proton exchange membrane fuel cell converts hydrogen and oxygen into electricity with zero emission1. The high cost and low durability of Pt-based electrocatalysts for oxygen reduction reaction hinder its wide applications2,3. The development of non-precious metal electrocatalysts also reaches the bottleneck because of the low activity and durability4,5. Here we rationally design a hybrid electrocatalyst consisting of atomically dispersed Pt and Fe single atoms and intermetallic PtFe alloy nanoparticles. The Pt mass activity of the hybrid catalyst is 3.5 times higher than that of commercial Pt/C in a fuel cell. More importantly, the fuel cell with an ultra-low Pt loading in the cathode (0.015 mgPt cm-2) shows unprecedented durability, with 93.6% activity retention after 100,000 cycles and no noticeable current drop at 0.6 V for at least 206 h. These results highlight the importance of the synergistic effects among active sites in hybrid electrocatalysts and provide an alternative way to design more active and durable low-Pt electrocatalysts for electrochemical devices.


2004 ◽  
Vol 19 (8) ◽  
pp. 2279-2284 ◽  
Author(s):  
Pan Mu ◽  
Tang Haolin ◽  
Mu Shichun ◽  
Yuan Runzhang

The purpose of this research is to investigate the feasibility of the synthesis of platinum/multi-wall carbon nanotube (Pt/MWNT) catalysts and such catalysts' application in fuel cells. The as-received MWNTs were purified and decorated by pretreatment. Infrared-spectrum indicates the carboxylic (-COOH) and carbonyl (-C=O) groups were introduced on the surface of the MWNTs after pretreatment. These functional groups will act as anchor sites for the Pt deposition. Then the Pt particles in nano scale were deposited on the surface of MWNTs by reduction of a solution of hexachloroplatinic acid. Transmission electron microscopy examination reveals that Pt particles are attached to the surface of MWNTs. If as-received MWNTs are not pretreated in the proper way, the Pt particle aggregates are mostly found on the open end of MWNTs. Occasionally Pt penetrated inside the tube of MWNTs. The relationship between the Pt particle morphology and the conditions of pretreatment and reduction reaction is discussed. After heat treatment, Pt particles recrystallized to form the Pt/MWNT catalysts. The Pt/MWNT catalysts were applied to a single cell and the test result shows a promising future of these catalysts with low Pt loading when applied in proton exchange membrane fuel cells (PEMFCs).


Nanomaterials ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 836
Author(s):  
Fatima Haidar ◽  
Mathieu Maas ◽  
Andrea Piarristeguy ◽  
Annie Pradel ◽  
Sara Cavaliere ◽  
...  

Platinum is the most employed electrocatalyst for the reactions taking place in energy converters, such as the oxygen reduction reaction in proton exchange membrane fuel cells, despite being a very low abundant element in the earth’s crust and thus extremely expensive. The search for more active electrocatalysts with ultra-low Pt loading is thus a very active field of investigation. Here, surface-limited redox replacement (SLRR) that utilizes the monolayer-limited nature of underpotential deposition (UPD) was used to prepare ultrathin deposits of Pt, using Te as sacrificial metal. Cyclic voltammetry and anodic potentiodynamic scanning experiments have been performed to determine the optimal deposition conditions. Physicochemical and electrochemical characterization of the deposited Pt was carried out. The deposit comprises a series of contiguous Pt islands that form along the grain interfaces of the Au substrate. The electrochemical surface area (ECSA) of the Pt deposit obtained after 5 replacements, estimated to be 18 m2/g, is in agreement with the ECSA of extended surface catalysts on flat surfaces.


2021 ◽  
Author(s):  
Xieweiyi Ye ◽  
Yakun Xue ◽  
Kaijia Li ◽  
Wen Tang ◽  
Xiao Han ◽  
...  

Improving the activity and durability of Pt-based electrocatalysts used in the acidic oxygen reduction reaction (ORR) is a great task for the commercial applications of proton-exchange membrane fuel cells. Alloying...


2021 ◽  
Author(s):  
Hong Zhu ◽  
Qingjun Chen ◽  
Jinghua Yu ◽  
Qian Zhou ◽  
Fanghui Wang ◽  
...  

The corrosion of carbon support is one of key factors causing deactivation of Pt-based oxygen reduction reaction (ORR) catalysts for proton exchange membrane fuel cells. In this work, a highly...


2021 ◽  
Author(s):  
Dongsheng Xia ◽  
Chenchen Yu ◽  
Yinghao Zhao ◽  
Yinping Wei ◽  
Haiyan Wu ◽  
...  

The severe degradation of Fe-N-C electrocatalysts during long-term oxygen reduction reaction (ORR) has become a major obstacle for application in proton-exchange membrane fuel cells. Understanding the degradation mechanism and regeneration...


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