Investigation of the Ethanol Electro-Oxidation in Alkaline Membrane Electrode Assembly by Differential Electrochemical Mass Spectrometry

Fuel Cells ◽  
2007 ◽  
Vol 7 (5) ◽  
pp. 417-423 ◽  
Author(s):  
V. Rao ◽  
Hariyanto ◽  
C. Cremers ◽  
U. Stimming
2018 ◽  
Vol 6 (1) ◽  
pp. 581
Author(s):  
H. Hariyanto ◽  
Widodo W. Purwanto ◽  
Roekmijati W. Soemantojo

In this present work, a systematically study on 20% PtCeO2/C catalyst for ethanol electro-oxidation in direct ethanol fuel cell were carried out. For cathode catalyst, a commercial catalyst of 40% Pt/C from ETEK was applied. Catalysts were printed on to carbon paper of TGPH 060 and sandwiched into membrane electrode assembly (MEA) and then arranged infitel cell with the geometric area 1.2 cm2. As an electrolyte, we used Nafion 117 from Du Pont. On-line Differential Electrochemical Mass Spectrometry (DEMS) measurement infuel cell setup was carried out in order to determine the activity and selectivity which was indicated by result of Faradaic current and CO2 current efficiency of ethanol electro-oxidation respectively. PtCeO2/C was significantly improving the selectivity of CO formation n comparison to the commercial catalyst of 20% Pt/C from A/fa Aesar- Johnson Mattews. Increasing of" selectivity was shown by the increase of CO2 current efficiency of ethanol oxidation of about 20 percent in comparison to references catalyst of 20% Pt/C (AlfaAesar-JM).Keywords: Ceria, Membrane Electrode Assembly (MEA), DEMS, Ethanol Electro-OxidationAbstrakPada peneletian ini dilakukan kajian sistematis terhadap katalis 20% PtCeO2/C yang akan digunakan pada elektro-oksidasi etanol pada sel bahan bakar etanol langsung. Untuk katalis katoda, digunakan katalis komersial 40% Pt/C dari ETEK. Katalis tersebut diaplikasikan pada kertas karbon TGPH 060 dan diselipkan pada rangkaian membran electroda (MEA) dan kemudian disusun pada sel bahan bakar yang memiliki luas geometris 1.2 cm2. Sebagai elektrolit, digunakan Nafion 117 produksi Du Pont. Pengukuran On-line oleh Spektrometri Massa Elektrokimia Diferensial atau Differential Electrochemical Mass Spectrometry (DEMS) pada pemasangan sel bahan bakar telah dilakukan untuk menentukan aktivitas dan selektivitasnya yang dapat ditunjukkan masing-masing oleh hasil arus Faradik dan efisiensi arus CO2 dari elektro-oksidasi etanol. Dari hasil percobaan diperoleh bahwa PtCeO2/C dapat secara signifikan meningkatkan selektivitas untuk membentuk CO2 dibandingkan terhadap katalis komersial 20% Pt/C dari A/fa Aesar-Johnson Mattews. Kenaikan selektivitas ditunjukkan oleh kenaikan efisiensi arus CO2pada oksidasi ethanol sebesar 20 persen dibandingkan terhadap katalis rujukan 20% Pt/C (AlfaAesar-JM).Kata Kunci: Ceria, Membrane Electrode Assembly (MEA), DEMS, Elektro-Oksidasi Etanol


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ning Wang ◽  
Aoni Xu ◽  
Pengfei Ou ◽  
Sung-Fu Hung ◽  
Adnan Ozden ◽  
...  

AbstractMetal borides/borates have been considered promising as oxygen evolution reaction catalysts; however, to date, there is a dearth of evidence of long-term stability at practical current densities. Here we report a phase composition modulation approach to fabricate effective borides/borates-based catalysts. We find that metal borides in-situ formed metal borates are responsible for their high activity. This knowledge prompts us to synthesize NiFe-Boride, and to use it as a templating precursor to form an active NiFe-Borate catalyst. This boride-derived oxide catalyzes oxygen evolution with an overpotential of 167 mV at 10 mA/cm2 in 1 M KOH electrolyte and requires a record-low overpotential of 460 mV to maintain water splitting performance for over 400 h at current density of 1 A/cm2. We couple the catalyst with CO reduction in an alkaline membrane electrode assembly electrolyser, reporting stable C2H4 electrosynthesis at current density 200 mA/cm2 for over 80 h.


Author(s):  
Xi Yin ◽  
Ling Lin ◽  
Hoon T. Chung ◽  
Ulises Martinez ◽  
Andrew M. Baker ◽  
...  

Finding a low-cost and stable electrocatalyst for hydrogen evolution reaction (HER) as a replacement for scarce and expensive precious metal catalysts has attracted significant interest from chemical and materials research communities. Here, we demonstrate an organic catalyst based on 2,2’-dipyridylamine (dpa) molecules adsorbed on carbon surface, which shows remarkable hydrogen evolution activity and performance durability in strongly acidic polymer electrolytes without involving any metal. The HER onset potential at dpa adsorbed on carbon has been found to be less than 50 mV in sulfuric acid and in a Nafion-based membrane electrode assembly (MEA). At the same time, this catalyst has shown no performance loss in a 60-hour durability test. The HER reaction mechanisms and the low onset overpotential in this system are revealed based on electrochemical study. Density functional theory (DFT) calculations suggest that the pyridyl-N functions as the active site for H adsorption with a free energy of -0.13 eV, in agreement with the unusually low onset overpotential for an organic molecular catalyst.<br>


2019 ◽  
Author(s):  
Xi Yin ◽  
Ling Lin ◽  
Hoon T. Chung ◽  
Ulises Martinez ◽  
Andrew M. Baker ◽  
...  

Finding a low-cost and stable electrocatalyst for hydrogen evolution reaction (HER) as a replacement for scarce and expensive precious metal catalysts has attracted significant interest from chemical and materials research communities. Here, we demonstrate an organic catalyst based on 2,2’-dipyridylamine (dpa) molecules adsorbed on carbon surface, which shows remarkable hydrogen evolution activity and performance durability in strongly acidic polymer electrolytes without involving any metal. The HER onset potential at dpa adsorbed on carbon has been found to be less than 50 mV in sulfuric acid and in a Nafion-based membrane electrode assembly (MEA). At the same time, this catalyst has shown no performance loss in a 60-hour durability test. The HER reaction mechanisms and the low onset overpotential in this system are revealed based on electrochemical study. Density functional theory (DFT) calculations suggest that the pyridyl-N functions as the active site for H adsorption with a free energy of -0.13 eV, in agreement with the unusually low onset overpotential for an organic molecular catalyst.<br>


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