Enhanced catalytic activity of low-Pt content nanocatalysts supported on hollow carbon spheres for the ORR in alkaline media

MRS Advances ◽  
2020 ◽  
Vol 5 (57-58) ◽  
pp. 2961-2972
Author(s):  
P.C. Meléndez-González ◽  
E. Garza-Duran ◽  
J.C. Martínez-Loyola ◽  
P. Quintana-Owen ◽  
I.L. Alonso-Lemus ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Anion Exchange ◽  
Average Particle Size ◽  
Synthesis Method ◽  
Alkaline Media ◽  
High Catalytic Activity ◽  
Average Particle ◽  
Carbon Spheres ◽  
Hollow Carbon ◽  
Hollow Carbon Spheres

In this work, low-Pt content nanocatalysts (≈ 5 wt. %) supported on Hollow Carbon Spheres (HCS) were synthesized by two routes: i) colloidal conventional polyol, and ii) surfactant-free Bromide Anion Exchange (BAE). The nanocatalysts were labelled as Pt/HCS-P and Pt/HCS-B for polyol and BAE, respectively. The physicochemical characterization of the nanocatalysts showed that by following both methods, a good control of chemical composition was achieved, obtaining in addition well dispersed nanoparticles of less than 3 nm TEM average particle size (d) on the HCS. Pt/HCS-B contained more Pt0 species than Pt/HCS-P, an effect of the synthesis method. In addition, the structure of the HCS remains more ordered after BAE synthesis, compared to polyol. Regarding the catalytic activity for the Oxygen Reduction Reaction (ORR) in 0.5 M KOH, Pt/HCS-P and Pt/HCS-B showed a similar performance in terms of current density (j) at 0.9 V vs. RHE than the benchmark commercial 20 wt. % Pt/C. However, Pt/HCS-P and Pt/HCS-B demonstrated a 6 and 5-fold increase in mass catalytic activity compared to Pt/C, respectively. A positive effect of the high specific surface area of the HCS and its interactions with metal nanoparticles and electrolyte, which promoted the mass transfer, increased the performance of Pt/HCS-P and Pt/HCS-B. The high catalytic activity showed by Pt/HCS-B and Pt/HCS-P for the ORR, even with a low-Pt content, make them promising cathode nanocatalysts for Anion Exchange Membrane Fuel Cells (AEMFC).

Surface Functionalization of Ordered Mesoporous Hollow Carbon Spheres with Ru Organometallic Compounds as Supports of Low-Pt Content Nanocatalysts for Alkaline Hydrogen and Oxygen Evolution Reactions

MRS Advances ◽  
2020 ◽  
Vol 5 (57-58) ◽  
pp. 2973-2989
Author(s):  
J.C. Martínez-Loyola ◽  
I.L. Alonso-Lemus ◽  
M.E. Sánchez-Castro ◽  
B. Escobar-Morales ◽  
J.R. Torres-Lubián ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
High Performance ◽  
Pt Nanoparticles ◽  
Organometallic Compounds ◽  
High Catalytic Activity ◽  
Carbon Spheres ◽  
Ordered Mesoporous ◽  
Electrochemical Water Splitting ◽  
Hollow Carbon ◽  
Hollow Carbon Spheres

AbstractHerein, we report a methodology that leads to the formation of Ru metallic sites, followed by the development and anchorage of Pt-Ru alloyed nanoparticles on the surface of Ordered Mesoporous Hollow Carbon Spheres (OMHCS). Along with the Ru sites, it is demonstrated that the functionalization promotes the formation of functional groups on the surface of the OMHCS. In a first stage, OMHCS are functionalized with the [(η6-C6H5OCH2CH2OH)RuCl2]2 (Ru-dim) and [(η6-C6H4CH(CH3)2CH3)RuCl2]2 (Ru-cym) organometallic compounds. Afterwards, Pt nanoparticles are dispersed by the microwave-assisted polyol method over the functionalized supports obtaining the low-metal content 5 wt. % Pt/OMHCSRu-dim and Pt/OMHCSRu-cym nanocatalysts. The degree of Ru alloyed is found to be around 35%. The low-Pt content Pt/OMHCSRu-cym and Pt/OMHCSRu-dim exhibit a higher catalytic activity for the Oxygen (OER) and the Hydrogen (HER) Evolution Reactions than the Pt/C benchmark and the Pt/OMHCS nanocatalysts. The overpotential for the OER at 10 mA cm-2 (ηOER) is 300 mV and 210 mV smaller at Pt/OMHCSRu-cym and Pt/OMHCSRu-dim compared to Pt/C, respectively. The corresponding values of the HER at -10 mA cm-2 (ηHER) are 14 and 18 mV smaller, respectively. The high catalytic activity of Pt/OMHCSRu-cym and Pt/OMHCSRu-dim has been attributed in part to the presence of Ru0 and RuO2 species from organometallic functionalization, and the modification of the d-valence band of Pt. Their high performance for the OER and the HER opens new lines of research for the design of nanocatalysts for alkaline electrochemical water splitting.

Synthesis of Ni@MWCNTs Magnetic Nanocatalysts and their Catalytic Activity towards 4-Nitrophenol Reduction

2012 ◽  
Vol 531 ◽  
pp. 358-361 ◽  
Author(s):  
Ming Mei Zhang ◽  
Qian Sun ◽  
Ji Min Xie
Keyword(s):  
Electron Microscopy ◽  
Catalytic Activity ◽  
Average Particle Size ◽  
Chemical Vapor ◽  
High Catalytic Activity ◽  
Average Particle ◽  
Ni Nanoparticles ◽  
Nitrophenol Reduction ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

A well-dispersed Ni nanoparticles on multi-walled carbon nanotubes (Ni@MWCNTs) was prepared by chemical vapor deposition (CVD) method using a vacuum quartz tube furnace at the temperature of 600°C. The scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD) were performed to characterize the synthesized catalyst. It shows an unfirom dispersion of Ni nanoparticles on MWCNTs with the average particle size of 8.6 nm. The as synthesized catalyst was applied in a redox reaction of 4-nitrophenol, which showed very high catalytic activity, stability and well conversion. The catalyst can be easily separated due to the magnetical performance

scholarly journals Preparation and Electrochemical Performance of a Graphene Cathode Catalyst Decorated With Pt by Prolysis

2022 ◽  
Vol 9 ◽  
Author(s):  
Xi Wang ◽  
Ying Ren ◽  
Ni Suo ◽  
Guifeng Zhang
Keyword(s):  
Catalytic Activity ◽  
Platinum Catalyst ◽  
Retention Rate ◽  
Average Particle Size ◽  
Technical Problem ◽  
Pt Catalyst ◽  
High Catalytic Activity ◽  
Average Particle ◽  
Chloroplatinic Acid ◽  
Platinum Particles

For fuel cells, to produce high-quality and low-platinum catalyst is a pressing technical problem. In this study, graphene cathode catalysts with controllable platinum content were decorated by pyrolyzing chloroplatinic acid under various process parameters to obtain a high catalytic activity and durability. The results show that platinum particles generated by pyrolyzing chloroplatinic acid are uniformly loaded on graphene without agglomeration. The average particle size of platinum particles is about 2.12 nm. The oxygen reduction reaction catalytic activity of catalyst samples first increases, then decreases with increasing platinum loading in cyclic voltammetry and LSV. Compared with the commercial Pt/C (20 wt% Pt) catalyst, the initial potential and the current density retention rate of the catalyst decorated with 8% platinum are 55 mV and 23.7% higher, respectively. From i-t curves, it was found that the stability of the catalyst prepared in this paper was improved compared with the commercial Pt/C catalyst. The catalysts prepared in the present research exhibits superior catalytic activity and stability.

N-doped hierarchical porous hollow carbon spheres with multi-cavities for high performance Na-ion storage

2021 ◽  
Vol 506 ◽  
pp. 230170
Author(s):  
Lantao Liu ◽  
Xiangyu Sun ◽  
Yue Dong ◽  
Dengke Wang ◽  
Zheng Wang ◽  
...  
Keyword(s):  
High Performance ◽  
Carbon Spheres ◽  
Hierarchical Porous ◽  
Ion Storage ◽  
Hollow Carbon ◽  
Hollow Carbon Spheres

Recent progress on the design of hollow carbon spheres to host sulfur in room-temperature sodium–sulfur batteries

2020 ◽  
Vol 35 (6) ◽  
pp. 630-645
Author(s):  
Jia-ying Yang ◽  
Hao-jie Han ◽  
Hlib Repich ◽  
Ri-cheng Zhi ◽  
Chang-zhen Qu ◽  
...  
Keyword(s):  
Room Temperature ◽  
Recent Progress ◽  
Carbon Spheres ◽  
Hollow Carbon ◽  
Sodium Sulfur ◽  
Hollow Carbon Spheres

Surface Polymerization and Controlled Pyrolysis: Tailorable Synthesis of Bumpy Hollow Carbon Spheres for Energy Storage

Langmuir ◽  
2021 ◽  
Vol 37 (13) ◽  
pp. 4007-4015
Author(s):  
Qianyi Tao ◽  
Zhifeng Zhu ◽  
Sunjie Ye ◽  
Gaojian Lin ◽  
Hui Chen ◽  
...  
Keyword(s):  
Energy Storage ◽  
Carbon Spheres ◽  
Surface Polymerization ◽  
Hollow Carbon ◽  
Hollow Carbon Spheres

Nitrogen-doped hollow carbon spheres with a wrinkled surface: their one-pot carbonization synthesis and supercapacitor properties

2016 ◽  
Vol 52 (78) ◽  
pp. 11693-11696 ◽  
Author(s):  
Lei Liu ◽  
Shi-Da Xu ◽  
Qing Yu ◽  
Feng-Yun Wang ◽  
Hui-Ling Zhu ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Core Shell ◽  
Carbon Spheres ◽  
Melamine Formaldehyde ◽  
One Pot ◽  
Nitrogen Doped ◽  
Wrinkled Surface ◽  
Hollow Carbon ◽  
Hollow Carbon Spheres

Nitrogen-doped hollow carbon spheres with a wrinkled surface were synthesized through direct pyrolysis of core–shell structured graphene oxide–resol@melamine formaldehyde composites.

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