One-pot surfactant-free synthesis of high surface area ternary alloys, PtMCo/C (M = Cr, Mn, Fe, Ni, Cu) with enhanced electrocatalytic activity and durability for PEM fuel cell application

2016 ◽  
Vol 41 (22) ◽  
pp. 9320-9331 ◽  
Author(s):  
K. Mohanraju ◽  
L. Cindrella
2016 ◽  
Vol 40 (10) ◽  
pp. 8681-8695 ◽  
Author(s):  
Karuppannan Mohanraju ◽  
Govindarajan Kousik ◽  
Louis Cindrella

High surface area core/shell nanostructures of Pt covered Pd alloys were synthesized and they exhibited enhanced electrocatalytic activity in oxygen reduction reactions.


2007 ◽  
Vol 52 (13) ◽  
pp. 4532-4538 ◽  
Author(s):  
Hansan Liu ◽  
Chaojie Song ◽  
Yuanhua Tang ◽  
Jianlu Zhang ◽  
Jiujun Zhang

2013 ◽  
Vol 34 ◽  
pp. 153-156 ◽  
Author(s):  
Jozsef Speder ◽  
Alessandro Zana ◽  
Ioannis Spanos ◽  
Jacob J.K. Kirkensgaard ◽  
Kell Mortensen ◽  
...  

Nanomaterials ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 854 ◽  
Author(s):  
Hanbo Xiao ◽  
Cheng-an Tao ◽  
Yujiao Li ◽  
Xianzhe Chen ◽  
Jian Huang ◽  
...  

Herein, a facile dopamine assisted one-pot synthesis approach is proposed for the preparation of porous carbon with a specific surface area (SSA) up to 2593 m2/g through the direct pyrolysis of a mixture of glucose, NH4Cl, and dopamine hydrochloride (DAH). The glucose is adopted as the carbon source and foaming agent, NH4Cl is used as the blowing agent, and DAH is served as collaborative carbon precursor as well as the nitrogen source for the first time. The effect of dopamine on the component, structure, and SSA of the as-prepared porous carbon materials are systematically studied. The moderate addition of dopamine, which influences the condensation and polymerization of glucose, matches better with ammonium salt decomposition. The SSA of porous carbon increases first and then decreases with the increasing amount of dopamine. In our case, the porous carbon produced with 5 wt% dopamine (PC-5) achieves the maximum SSA of up to 2593 m2/g. Accordingly, it also shows the greatest electrochemical performance. The PC-5 shows a capacitance of 96.7 F/g calculated from the discharge curve at 1 A/g. It also has a good capacitive rate capacity, the specific capacitance can still maintain 80%, even at a high current density of 10 A/g. Moreover, PC-5 exhibits a good cycling stability of 98.1% capacitive retention after 1000 cycles. The proposed method may show promising prospects for preparing porous carbon materials as advanced energy storage materials, storage, and catalyst supports.


Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1685
Author(s):  
Katarzyna Morawa Eblagon ◽  
Anna Malaika ◽  
Karolina Ptaszynska ◽  
Manuel Fernando R. Pereira ◽  
José Luís Figueiredo

The cascade dehydration of glucose to 5-hydroxymethylfurfural (HMF) was carried out in water over a series of Nb2O5 catalysts, which were derived from the thermal treatment of niobic acid at 300 and 550 °C, under air or inert atmosphere. Amorphous niobic acid showed high surface area (366 m2/g) and large acidity (2.35 mmol/g). With increasing the temperature of the thermal treatment up to 550 °C, the amorphous Nb2O5 was gradually transformed into a pseudohexagonal phase, resulting in a decrease in surface area (27–39 m2/g) and total acidity (0.05–0.19 mmol/g). The catalysts’ performance in cascade dehydration of glucose realized in pure water was strongly influenced by the total acidity of these materials. A remarkable yield of 37% HMF in one-pot reaction in water was achieved using mesoporous amorphous niobium oxide prepared by thermal treatment of niobic acid at 300 °C in air. The best-performing catalyst displayed a total acidity lower than niobic acid (1.69 mmol/g) which afforded a correct balance between a high glucose conversion and limited further conversion of the target product to numerous polymers and humins. On the other hand, the treatment of niobic acid at 550 °C, independently of the atmosphere used during the sample preparation (i.e., air or N2), resulted in Nb2O5 catalysts with a high ratio of Lewis to Brønsted acid sites and poor total acidity. These materials excelled at catalyzing the isomerization step in the tandem process.


2020 ◽  
Vol 56 (14) ◽  
pp. 2095-2098 ◽  
Author(s):  
Eri Hayashi ◽  
Yui Yamaguchi ◽  
Yusuke Kita ◽  
Keigo Kamata ◽  
Michikazu Hara

High-surface-area β-MnO2 nanoparticles exhibited high activity for the one-pot oxidative sulfonamidation of thiols to sulfonamides using O2 and NH3.


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