Effects of support and additive on oxidation state and activity of Pt catalyst in propane combustion

Yoshida, Hisao; Yazawa, Yoshiteru; Hattori, Tadashi

doi:10.1016/j.cattod.2003.10.001

Cited by 145 publications

(100 citation statements)

References 59 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The fact that the platinum surface is oxidized under these conditions (Figures 3b and 4b) is corroborated by the low values of the open-circuit catalytic rate, in view of the fact that oxidation of the platinum surface results in decrease of the catalytic activity for propane combustion [11,39]. Oxidized state of the platinum catalyst surface has also been reported in the case of propane oxidation on Pt/YSZ between 250 and 450°C under oxygen-rich or stoichiometric conditions [32].…”

Section: Discussionsupporting

confidence: 53%

“…Oxidized state of the platinum catalyst surface has also been reported in the case of propane oxidation on Pt/YSZ between 250 and 450°C under oxygen-rich or stoichiometric conditions [32]. The quite pronounced, in terms of rate enhancement ratios, electrochemical promotion observed with platinum catalyst film Pt2 under the conditions of Figures 3b and 4b (P O 2 =P C 3 H 8 % 3:1 to 3.4, T=480-520°C) and the similar rate enhancement ratios observed in this case for positive and negative overpotential application can be attributed to a large extent to decomposition of the surface platinum oxide, in view of the fact that metallic platinum shows higher activity for propane combustion [11,39]. This explanation is in agreement with the observed increase, under oxidizing conditions, in the catalytic activity for propane combustion of supported platinum catalysts via addition of electronegative additives [14], which has been attributed to the increase in the oxidation-resistance of the platinum catalyst.…”

Section: Discussionsupporting

confidence: 51%

See 1 more Smart Citation

Electrochemical promotion of the oxidation of propane on Pt/YSZ and Rh/YSZ catalyst-electrodes

Kotsionopoulos

Bebelis

2005

J Appl Electrochem

View full text Add to dashboard Cite

The effect of electrochemical promotion (EP) or non-faradaic electrochemical modification of catalytic activity (NEMCA) was studied in the catalytic reaction of the total oxidation of propane on Pt and Rh films deposited on Y 2 O 3 -stabilized-ZrO 2 (or YSZ), an O 2) conductor, in the temperature range 420-520°C. In the case of Pt/YSZ and for oxygen to propane ratios lower than the stoichiometric ratio it was found that the rate of propane oxidation could be reversibly enhanced by application of both positive and negative overpotentials (''inverted volcano'' behavior), by up to a factor of 1350 and 1130, respectively. The induced rate increase Dr exceeded the corresponding electrochemically controlled rate I/2F of O 2) transfer through the solid electrolyte, resulting in absolute values of the apparent faradaic efficiency K=Dr/(I/2F) up to 2330. The Rh/YSZ system exhibited similar EP behavior. Abrupt changes in the oxidation state of the rhodium catalyst, accompanied by changes in the catalytic rate, were observed by changing the O 2 to propane ratio and catalyst potential. The highest rate increases, by up to a factor of 6, were observed for positive overpotentials with corresponding absolute values of faradaic efficiency K up to 830. Rate increases by up to a factor of 1.7 were observed for negative overpotentials. The observed EP behavior is explained by taking into account the mechanism of the reaction and the effect of catalyst potential on the binding strength of chemisorbed reactants and intermediates and on the oxidative state of the catalyst surface.

show abstract

Section: Discussionsupporting

confidence: 53%

Section: Discussionsupporting

confidence: 51%

Electrochemical promotion of the oxidation of propane on Pt/YSZ and Rh/YSZ catalyst-electrodes

Kotsionopoulos

Bebelis

2005

J Appl Electrochem

View full text Add to dashboard Cite

show abstract

“…Formation of binary oxides of sodium and platinum, e.g. Na x Pt 3 O 4 [22][23][24], via an electrochemical reaction similar to Reaction 2 may also contribute to the appearance of these peaks. It is noted that the multiplicity of peaks related to decomposition of sodium oxide phases (Figs.…”

Section: Resultsmentioning

confidence: 96%

Electrochemical characterization of the Pt/β′′–Al2O3 system under conditions of in situ electrochemical modification of catalytic activity for propane combustion

Kotsionopoulos

Bebelis

2010

J Appl Electrochem

View full text Add to dashboard Cite

Linear sweep and cyclic voltammetry were used for electrochemical characterization of the Pt/sodiumb 00 -Al 2 O 3 system and investigation of the phases formed upon electrochemical pumping of sodium ions to the Pt catalyst-electrode under conditions of propane combustion or under mixtures of O 2 or CO 2 with helium, at temperatures between 320 and 480°C. The number, position and magnitude of the peaks in the obtained voltammograms were found to depend on gas phase composition, temperature, and pre-scan (initial polarization) conditions. The results showed that under conditions of propane combustion more than one sodium phases can be formed as a result of electrochemical pumping of sodium ions to the Pt catalyst. The related electrochemical reactions and the identity of these sodium phases, which correspond mainly to carbonate or bicarbonate phases but also to oxide phases, are discussed on the basis of the obtained results and those of former studies.

show abstract

“…However, the oxidation state is another important factor which decides the activity of the catalyst. It has been observed that platinum in metallic or zero oxidation state shows higher catalytic activity than its corresponding oxidized species [34]. XPS was used as a quantitative technique to measure the elemental composition and their oxidation states present in the samples so as to illustrate the Although the percentage of graphitic carbon in all samples is quite high, but there is visible contribution of other species also.…”

Section: Electrochemical Characterizationmentioning

confidence: 99%

Processing of pristine carbon nanotube supported platinum as catalyst for PEM fuel cell

Gupta¹,

Maheshwari²,

Sasikala

et al. 2014

Mater Renew Sustain Energy

View full text Add to dashboard Cite

Pristine multiwalled carbon nanotube supported platinum catalyst (Pt/CNT) has been developed by reduction of Pt salt on CNTs in ethylene glycol solution. The reactions were carried out under different pH conditions followed by detailed physical and electrochemical characterizations. The I-V performance of unit Polymer electrolyte membrane fuel cell shows a peak Power density of 325 mWcm -2 with catalyst prepared in alkaline medium, an increase of [250 % as compared to 87 mWcm -2 obtained, while employing catalyst prepared in acidic medium and tested under similar conditions. This is attributed not only to the uniform distribution of Pt nanoparticles with small particle size in range of 2-3 nm, but also to the metallic or zero oxidation state in which most of the Pt is present when reduction is carried out in alkaline medium.

show abstract

Effects of support and additive on oxidation state and activity of Pt catalyst in propane combustion

Cited by 145 publications

References 59 publications

Electrochemical promotion of the oxidation of propane on Pt/YSZ and Rh/YSZ catalyst-electrodes

Electrochemical promotion of the oxidation of propane on Pt/YSZ and Rh/YSZ catalyst-electrodes

Electrochemical characterization of the Pt/β′′–Al2O3 system under conditions of in situ electrochemical modification of catalytic activity for propane combustion

Processing of pristine carbon nanotube supported platinum as catalyst for PEM fuel cell

Contact Info

Product

Resources

About