1. Αποθετήριο Παραδοτέων Υποτρόφων Δράσεων ΕΣΠΑ Τριτοβάθμιας Εκπαίδευσης 2017-2023
2. Όλο το Αποθετήριο
3. Ερευνητικές ομάδες

Τύπος:	Ανακοίνωση σε συνέδριο
Τίτλος:	Pt-based bimetallic electrocatalysts for oxygen reduction reaction in alkaline medium
Συγγραφέας:	[EL] Μπάμπος, Γεώργιος[EN] Bampos, Georgios [EL] Διαμαντής, Αθανάσιος[EN] Diamantis, Athanasios [EL] Μπεμπέλης, Συμεών[EN] Bebelis, Symeon
Ημερομηνία:	27/06/2023
Περίληψη:	The less corrosive environment and the faster intrinsic kinetics of oxygen reduction reaction (ORR) in alkaline medium compared to acidic medium offer the advantage of possible use of electrocatalysts with low noble metal loading or non-noble metal electrocatalysts [1]. Towards this direction, many research efforts have focused on combining Pt with non-noble transition metals to synthesize electrocatalysts for ORR in alkaline media with reduced cost and, potentially, increased ORR activity, mainly owing to changes of the electronic properties of the active metal phase [1-3]. In the present work a series of 10 wt.% Pt-M (M: Ag, Co, Cu, Fe, Ni, Ru, Sn, Zn)/C bimetallic electrocatalysts supported on conductive carbon black (Vulcan XC72R), with a Pt:M atomic ratio equal to 3:1, were synthesized using the wet impregnation method followed by reduction under H2 flow at 300 oC for 2 h. A 10 wt.% Pt/C electrocatalyst, prepared in the same manner, was used as reference material. The specific surface area (SSA) and the structural characteristics of the synthesized electrocatalytic powders were determined employing N2 physisorption (BET method) and X-ray diffraction, respectively. The ORR activity of the electrocatalysts, in the form of thin films deposited on a glassy carbon electrode, was assessed in O2 saturated 0.1 M KOH solution using the thin-film rotating disk electrode (RDE) technique [5]. The electrochemically active surface area (ECSA) was determined for each electrocatalyst employing the CO stripping method [2]. The electrocatalysts were compared in terms of specific activity S.A. = Ik/ECSA (Fig. 1a) and mass activity M.A. = Ik/mPt (Fig. 1b), where Ik denotes the kinetic current and mPt the platinum mass. Figure1. Specific (a) and mass (b) activity of the tested electrocatalysts vs. ohmic drop free potential U-IR (mass transfer corrected Tafel plots) in 0.1 M KOH at room temperature Alloy formation was identified (by XRD) only in the case of Pt-Zn/C. The highest ECSA was exhibited by Pt/C and the lowest by the Pt-Sn/C. As shown in Fig. 1a, the highest specific activity (S.A) in the potential range from -0.15 to -0.45 V vs. Ag/AgCl was exhibited by Pt-Sn/C, while for -0.5 V vs. Ag/AgCl by the Pt/C and Pt-Ag/C electrocatalysts. Pt-Ni/C, Pt-Ru/C and Pt-Cu/C also showed high S.A. whereas Pt-Fe/C exhibited the lowest S.A. As shown in Fig. 1b, the highest mass activity (M.A.) was exhibited by Pt/C, followed by Pt-Ag/C. The Pt-Ru/C, Pt-Ni/C and Pt-Zn/C electrocatalysts also exhibited high M.A., whereas the M.A. of Pt-Fe/C was the lowest. Overall, the Pt-Ag/C electrocatalyst appeared promising for ORR in alkaline medium. Its enhanced ORR activity could be attributed to electronic interaction between Ag and Pt in the active metal phase, with concomitant alteration of its chemisorptive properties favorably for ORR on the basis of the ORR mechanism [1]. [1] Ge, X., Sumboja, A., Wuu, D., et al. (2015). ACS Catal. 5: 4643–4667 [2] Bampos, G., Sygellou, L., Bebelis, S. (2020). Catal. Today 355: 685-67 [3] Bampos, G., Bebelis, S., Kondarides, D.I., Verykios, X. (2017). Top. Catal. 60: 1260-1273 [4] Bampos, G., Tsatsos, S., Kyriakou, G., Bebelis, S. (2023). J. Electroanal. Chem. 928: 117008 [5] Schmidt, J., Gasteiger, H.A., Stäb, G. D., et al. (1998). J. Electrochem. Soc. 145:2354-2358
Γλώσσα:	Αγγλικά
Τόπος δημοσίευσης:	Toulouse, France
Σελίδες:	1
Θεματική κατηγορία:	[EL] Χημική μηχανική[EN] Chemical Engineering
Κάτοχος πνευματικών δικαιωμάτων:	© The Author(s) 2023
Όνομα εκδήλωσης:	13th European Symposium on Electrochemical Engineering (13thESEE2023)
Τοποθεσία εκδήλωσης:	Toulouse, France
Ημ/νία έναρξης εκδήλωσης:	26/06/2023
Ημ/νία λήξης εκδήλωσης:	29/06/2023
Σημειώσεις:	https://13thesee2023.sciencesconf.org/data/pages/A2a_13th_ESEE_Scientific_Program_ORALS_complet_2.pdf https://13thesee2023.sciencesconf.org/ This research was funded in the frame of the project “Perovskitic electrocatalysts for integrated systems of microbial electrolysis cells and anion exchange membrane fuel cells (Acronym: PERFORMANCE, project code: 82242)”, which was supported by the 3rd Call of Hellenic Foundation of Research and Innovation (H.F.R.I.) Research Projects for the support of Post-doctoral Researchers (fellowship of Dr. G. Bampos).
Εμφανίζεται στις συλλογές:	Ερευνητικές ομάδες