A facile synthetic route for highly durable mesoporous platinum thin film electrocatalysts based on graphene: morphological and support effects on the oxygen reduction reaction

2017 ◽  
Vol 5 (7) ◽  
pp. 3129-3135 ◽  
Author(s):  
Kie Yong Cho ◽  
Yong Sik Yeom ◽  
Heun Young Seo ◽  
Pradip Kumar ◽  
Kyung-Youl Baek ◽  
...  

Porous-structured platinum thin film electrocatalysts offer highly enhanced ORR activity and durability benefits based on a large surface area and interconnected nanostructure.

2011 ◽  
Vol 1311 ◽  
Author(s):  
Wisam J. Khudhayer ◽  
Nancy Kariuki ◽  
Deborah Myers ◽  
Ali Shaikh ◽  
Tansel Karabacak

ABSTRACTIn this work, we investigated the electrocatalytic oxygen reduction reaction (ORR) activity of vertically aligned, single-layer, carbon-free, and single crystal Pt nanorod arrays utilizing cyclic voltammetry (CV) and rotating-disk electrode (RDE) techniques. A glancing angle deposition (GLAD) technique was used to fabricate 200 nm long Pt nanorods, which corresponds to Pt loading of 0.16 mg/cm2, on glassy carbon (GC) electrode at a glancing angle of 85° as measured from the substrate normal. An electrode comprised of conventional carbon-supported Pt nanoparticles (Pt/C) was also prepared for comparison with the electrocatalytic ORR activity and stability of Pt nanorods. CV results showed that the Pt nanorod electrocatalyst exhibits a more positive oxide reduction peak potential compared to Pt/C, indicating that GLAD Pt nanorods are less oxophilic. In addition, a series of CV cycles in acidic electrolyte revealed that Pt nanorods are significantly more stable against electrochemically-active surface area loss than Pt/C. Moreover, room temperature RDE results demonstrated that GLAD Pt nanorods exhibit higher area-specific ORR activity than Pt/C. The enhanced electrocatalytic ORR activity of Pt nanorods is attributed to their larger crystallite size, single-crystal property, and the dominance of (110) crystal planes on the large surface area nanorods sidewalls, which has been found to be the most active plane for ORR. However, the Pt nanorods showed lower mass specific activity than the Pt/C electrocatalyst due to the large diameter of the Pt nanorods.


2012 ◽  
Vol 1446 ◽  
Author(s):  
Wisam J. Khudhayer ◽  
Nancy Kariuki ◽  
Deborah J. Myers ◽  
Ali U. Shaikh ◽  
Tansel Karabacak

ABSTRACTNanorod arrays of chromium (Cr) were grown on glassy carbon (GC) electrodes by a dc magnetron sputtering glancing angle deposition (GLAD) technique. The Cr nanorods were used as low-cost, high surface area, metallic supports for a conformal layer of Pt thin film catalyst, as a potential low-loading electrocatalyst for the oxygen reduction reaction (ORR) in polymer electrolyte membrane (PEM) fuel cells. A dc magnetron sputtering small angle deposition (SAD) technique was utilized for a conformal coating of Pt on Cr nanorods. The ORR activity of SAD-Pt/GLAD-Cr electrodes was investigated using cyclic voltammetry (CV) and rotating-disk electrode (RDE) techniques in a 0.1 M HClO4 solution at room temperature. A reference sample consisting of GLAD Cr nanorods coated with a Pt thin film deposited at normal incidence (θ = 0o) was prepared and compared with the SAD-Pt/GLAD-Cr nanorods. Compared to GLAD Cr nanorods coated with Pt thin film at θ = 0o, the SAD-Pt/GLAD-Cr nanorod electrode exhibited higher ECSA and area-specific and mass-specific ORR activity. These results indicate that the growth of catalyst layer on the base-metal nanorods by the SAD technique provides a more conformal and possibly a nanostructured coating, significantly enhancing the catalyst utilization.


2017 ◽  
Vol 8 (4) ◽  
pp. 351-365 ◽  
Author(s):  
Sebastian Proch ◽  
Shuhei Yoshino ◽  
Itaru Gunjishima ◽  
Satoru Kosaka ◽  
Naoko Takahashi ◽  
...  

RSC Advances ◽  
2016 ◽  
Vol 6 (81) ◽  
pp. 77786-77795 ◽  
Author(s):  
Nan Wang ◽  
Jingjun Liu ◽  
Weiwei Gu ◽  
Ye Song ◽  
Feng Wang

The interficial covalent bonds formed in La2O3/C hybrid are responsible for its enhanced ORR activity.


RSC Advances ◽  
2015 ◽  
Vol 5 (2) ◽  
pp. 1571-1580 ◽  
Author(s):  
Dongyoon Shin ◽  
Beomgyun Jeong ◽  
Myounghoon Choun ◽  
Joey D. Ocon ◽  
Jaeyoung Lee

An optimal catalyst testing methodology that could allow precise benchmarking to obtain standardized ORR activity is put forward.


Catalysts ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1354
Author(s):  
Vera Bogdanovskaya ◽  
Inna Vernigor ◽  
Marina Radina ◽  
Vladimir Sobolev ◽  
Vladimir Andreev ◽  
...  

In order to develop highly efficient and stable catalysts for oxygen reduction reaction (ORR) that do not contain precious metals, it is necessary to modify carbon nanotubes (CNT) and define the effect of the modification on their activity in the ORR. In this work, the modification of CNTs included functionalization by treatment in NaOH or HNO3 (soft and hard conditions, respectively) and subsequent doping with nitrogen (melamine was used as a precursor). The main parameters that determine the efficiency of modified CNT in ORR are composition and surface area (XPS, BET), hydrophilic–hydrophobic surface properties (method of standard contact porosimetry (MSP)) and zeta potential (dynamic light scattering method). The activity of CNT in ORR was assessed following half-wave potential, current density within kinetic potential range and the electrochemically active surface area (SEAS). The obtained results show that the modification of CNT with oxygen-containing groups leads to an increase in hydrophilicity and, consequently, SEAS, as well as the total (overall) current. Subsequent doping with nitrogen ensures further increase in SEAS, higher zeta potential and specific activity in ORR, reflected in the shift of the half-wave potential by 150 mV for CNTNaOH-N and 110 mV for CNTHNO3-N relative to CNTNaOH and CNTHNO3, respectively. Moreover, the introduction of N into the structure of CNTHNO3 increases their corrosion stability.


Sign in / Sign up

Export Citation Format

Share Document