Comparison of Catalytic Activities of Carbon Supported Pt and Pt-Ru Catalysts for Methanol Oxidation in Neutral and Basic Media by Cyclic Voltammetry

Abdul Sattar Ali KHAN; Riaz AHMED; Muhammad Latif MIRZA

Makale detayları

Comparison of Catalytic Activities of Carbon Supported Pt and Pt-Ru Catalysts for Methanol Oxidation in Neutral and Basic Media by Cyclic Voltammetry

Yazarlar:

Abdul Sattar Ali KHAN | Riaz AHMED | Muhammad Latif MIRZA

Yayıncı:

TUBITAK

Dergi:

Turkish Journal of Chemistry 2008 Vol.32 Issue 6, pp.743-753

Belge Tipi:

Makale

Yayın Tarihi:

5/2008

Belge Dili:

Türkçe

Document ID (Org No.):

2000728412

Sıklık:

İki Aylık

eISSN:

1303-6130

pISSN:

1300-0527

Özet:

 

The catalytic activities of an equal amount of 3 different  carbon supported catalysts containing 10% Pt, 20% Pt + 10% Ru, and  30% Pt were evaluated in neutral and basic media for methanol  oxidation by cyclic voltammetry.  The prominent oxidation peak for  methanol appeared in the forward anodic sweep at around 1.0 V in  neutral medium, while in basic medium it appeared at significantly  lower potential close to 0.2 V. The peak current for methanol  oxidation was higher on a catalyst containing higher Pt loading.  The  comparison of polarization behavior of 20% Pt + 10% Ru and 30% Pt  catalysts showed that the presence of Ru increases the catalytic  activity at the lower polarization region.  The enhancement of  catalytic activity by Ru was more obvious in basic medium as compared  with neutral medium.  The heterogeneous rate constants were evaluated  from peak current data.  At room temperature, the heterogeneous rate  constant for methanol oxidation on a given catalyst was higher in  basic medium as compared with neutral medium.  The effect of  temperature on peak current was investigated.  At lower temperature,  the catalytic activities were lower in neutral medium but approached  near that in basic medium at higher temperature owing to the higher  apparent enthalpy of activation D H*'' for methanol oxidation  in neutral medium.  The D H* values were calculated from the  analysis of peak current data and found to be in the range 24 to 27 kJ  mol-1 in neutral medium and 15 to 17 kJ mol-1 in basic medium.

 

The catalytic activities of an equal amount of 3 different  carbon supported catalysts containing 10% Pt, 20% Pt + 10% Ru, and  30% Pt were evaluated in neutral and basic media for methanol  oxidation by cyclic voltammetry.  The prominent oxidation peak for  methanol appeared in the forward anodic sweep at around 1.0 V in  neutral medium, while in basic medium it appeared at significantly  lower potential close to 0.2 V. The peak current for methanol  oxidation was higher on a catalyst containing higher Pt loading.  The  comparison of polarization behavior of 20% Pt + 10% Ru and 30% Pt  catalysts showed that the presence of Ru increases the catalytic  activity at the lower polarization region.  The enhancement of  catalytic activity by Ru was more obvious in basic medium as compared  with neutral medium.  The heterogeneous rate constants were evaluated  from peak current data.  At room temperature, the heterogeneous rate  constant for methanol oxidation on a given catalyst was higher in  basic medium as compared with neutral medium.  The effect of  temperature on peak current was investigated.  At lower temperature,  the catalytic activities were lower in neutral medium but approached  near that in basic medium at higher temperature owing to the higher  apparent enthalpy of activation D H*'' for methanol oxidation  in neutral medium.  The D H* values were calculated from the  analysis of peak current data and found to be in the range 24 to 27 kJ  mol-1 in neutral medium and 15 to 17 kJ mol-1 in basic medium.

Makale detayları

Comparison of Catalytic Activities of Carbon Supported Pt and Pt-Ru Catalysts for Methanol Oxidation in Neutral and Basic Media by Cyclic Voltammetry

Yazarlar: Abdul Sattar Ali KHAN | Riaz AHMED | Muhammad Latif MIRZA

Yayıncı: TUBITAK

Dergi: Turkish Journal of Chemistry 2008 Vol.32 Issue 6, pp.743-753

Belge Tipi: Makale

Yayın Tarihi: 5/2008

Belge Dili: Türkçe

Document ID (Org No.): 2000728412

Sıklık: İki Aylık

eISSN: 1303-6130

pISSN: 1300-0527

Sayı

Yazarlar:

Abdul Sattar Ali KHAN | Riaz AHMED | Muhammad Latif MIRZA

Yayıncı:

TUBITAK

Dergi:

Turkish Journal of Chemistry 2008 Vol.32 Issue 6, pp.743-753

Belge Tipi:

Makale

Yayın Tarihi:

5/2008

Belge Dili:

Türkçe

Document ID (Org No.):

2000728412

Sıklık:

İki Aylık

eISSN:

1303-6130

pISSN:

1300-0527