Evolution of Nanoporous Pt–Fe Alloy Nanowires by Dealloying and their Catalytic Property for Oxygen Reduction Reaction

Abstract

The short life and high cost of carbon-supported Pt nanoparticle catalysts (Pt/C) are two main problems with proton exchange membrane fuel cells. Porous Pt alloy nanowires have more durability and catalytic activity than Pt/C. Dealloying is a facile way to make nanoporous Pt. However, the process of porosity formation is diffi cult to control. In this paper, electrospinning and chemical dealloying techniques are used to make long, thin and yet nanoporous Pt-Fe alloy nanowires. The evolution of nanoporosity is observed and studied. It is found that non-uniform composition in the precursor PtFe 5 alloy nanowires helps the formation of nanoporous structure. The overall wire diameter is about 10-20 nm and the ligament diameter only 2-3 nm. These porous long nanowires interweave to form a self-supporting network with a high specifi c activity, 2.3 times that of conventional Pt/C catalysts, and also have better durability.

Preparation of carbon-supported PtM (M=Au, Pd, or Cu) nanorods and their application in oxygen reduction reaction

“…It seems that the I k of Pt NPs is comparable to that reported in the literatures [2,6] and I k and mass activity of PtM NRs are also superior to those of some state-of-the-art PtPd, PtFe, PtRu, and PtTi catalysts [2,14]. Besides, the I k of NRs is about 1.3-1.4 times higher than that of Pt NPs due to their preferential exposure of certain crystal facets and less surface defects bearing [6][7][8]. In addition, the ORR activity of Pt is known to increase in the order Pt(100) ≪ Pt(111) b Pt(110) in a nonadsorbing electrolyte such as HClO 4 [7,8].…”

Preparation of carbon-supported PtM (M=Au, Pd, or Cu) nanorods and their application in oxygen reduction reaction

“…It seems that the I k of Pt NPs is comparable to that reported in the literatures [2,6] and I k and mass activity of PtM NRs are also superior to those of some state-of-the-art PtPd, PtFe, PtRu, and PtTi catalysts [2,14]. Besides, the I k of NRs is about 1.3-1.4 times higher than that of Pt NPs due to their preferential exposure of certain crystal facets and less surface defects bearing [6][7][8]. In addition, the ORR activity of Pt is known to increase in the order Pt(100) ≪ Pt(111) b Pt(110) in a nonadsorbing electrolyte such as HClO 4 [7,8].…”

Computational Screening for Developing Optimal Intermetallic Transition Metal Pt-Based ORR Catalysts at the Predictive Volcano Peak

“…Specific compositions of MN in Pt-skin Pt 3 (MN) 1 , which fall the closest to this predicted volcano maximum, include on the left leg, Os 2 Ir 2 , Ru 2 Cu 2 , Os 2 Ru 2 , Co 2 Pd 2 , Ru 2 Rh 2 , Ru 2 Pd 2 , and Ir 2 Pd 2 and on the right leg, Ru 2 Ir 2 , Os 2 Pd 2 , Ru 4 , Rh 2 Ir 2 , Rh 2 Ni 2 , Ni 4 , and then the base-metal ternary intermetallics previously reported . Many of these combinations of Os, Pd, Cu, and Rh compositions are showing performances similar to or better than those recently reported for bimetallic or ternary Pt-based systems. ,− ,,− We note that due to limitations of the computational model, calculation accuracy, and cutoff criteria, values within ∼0.03 eV for the descriptor Δ E ads O* should be treated as identical.…”

Composition-Tunable PtCu Alloy Nanowires and Electrocatalytic Synergy for Methanol Oxidation Reaction

“…The enhanced electrocatalytic performance is likely linked to the increased stability of the NW structure. This likely contributes to the increased resistance of the NWs to dissolution, aggregation, or Ostwald ripening in comparison with Pt/C catalyst in the acidic electrolyte, as suggested earlier. , …”

“…This likely contributes to the increased resistance of the NWs to dissolution, aggregation, or Ostwald ripening in comparison with Pt/C catalyst in the acidic electrolyte, as suggested earlier. 14,47 In comparison with the data for the above PtCu NWs with low Pt%, Pt 70 Cu 30 alloy NWs (Figure S6 A) exhibited a mass activity of 322 mA mg −1 , which is slightly higher than that of commercial Pt/C catalyst (293 mA mg −1 ) and much lower than that of pure Pt NWs(483 mA mg −1 ). The stability of Pt 70 Cu 30 alloy NWs (Figure S6 B) was also worse than commercial Pt/C catalyst.…”

Preparation of carbon-supported PtM (M=Au, Pd, or Cu) nanorods and their application in oxygen reduction reaction

“…It seems that the I k of Pt NPs is comparable to that reported in the literatures [2,6] and I k and mass activity of PtM NRs are also superior to those of some state-of-the-art PtPd, PtFe, PtRu, and PtTi catalysts [2,14]. Besides, the I k of NRs is about 1.3-1.4 times higher than that of Pt NPs due to their preferential exposure of certain crystal facets and less surface defects bearing [6][7][8]. In addition, the ORR activity of Pt is known to increase in the order Pt(100) ≪ Pt(111) b Pt(110) in a nonadsorbing electrolyte such as HClO 4 [7,8].…”

Computational Screening for Developing Optimal Intermetallic Transition Metal Pt-Based ORR Catalysts at the Predictive Volcano Peak

“…Specific compositions of MN in Pt-skin Pt 3 (MN) 1 , which fall the closest to this predicted volcano maximum, include on the left leg, Os 2 Ir 2 , Ru 2 Cu 2 , Os 2 Ru 2 , Co 2 Pd 2 , Ru 2 Rh 2 , Ru 2 Pd 2 , and Ir 2 Pd 2 and on the right leg, Ru 2 Ir 2 , Os 2 Pd 2 , Ru 4 , Rh 2 Ir 2 , Rh 2 Ni 2 , Ni 4 , and then the base-metal ternary intermetallics previously reported . Many of these combinations of Os, Pd, Cu, and Rh compositions are showing performances similar to or better than those recently reported for bimetallic or ternary Pt-based systems. ,− ,,− We note that due to limitations of the computational model, calculation accuracy, and cutoff criteria, values within ∼0.03 eV for the descriptor Δ E ads O* should be treated as identical.…”

Composition-Tunable PtCu Alloy Nanowires and Electrocatalytic Synergy for Methanol Oxidation Reaction

“…The enhanced electrocatalytic performance is likely linked to the increased stability of the NW structure. This likely contributes to the increased resistance of the NWs to dissolution, aggregation, or Ostwald ripening in comparison with Pt/C catalyst in the acidic electrolyte, as suggested earlier. , …”

“…This likely contributes to the increased resistance of the NWs to dissolution, aggregation, or Ostwald ripening in comparison with Pt/C catalyst in the acidic electrolyte, as suggested earlier. 14,47 In comparison with the data for the above PtCu NWs with low Pt%, Pt 70 Cu 30 alloy NWs (Figure S6 A) exhibited a mass activity of 322 mA mg −1 , which is slightly higher than that of commercial Pt/C catalyst (293 mA mg −1 ) and much lower than that of pure Pt NWs(483 mA mg −1 ). The stability of Pt 70 Cu 30 alloy NWs (Figure S6 B) was also worse than commercial Pt/C catalyst.…”

Preparation of carbon-supported PtM (M=Au, Pd, or Cu) nanorods and their application in oxygen reduction reaction

“…It seems that the I k of Pt NPs is comparable to that reported in the literatures [2,6] and I k and mass activity of PtM NRs are also superior to those of some state-of-the-art PtPd, PtFe, PtRu, and PtTi catalysts [2,14]. Besides, the I k of NRs is about 1.3-1.4 times higher than that of Pt NPs due to their preferential exposure of certain crystal facets and less surface defects bearing [6][7][8]. In addition, the ORR activity of Pt is known to increase in the order Pt(100) ≪ Pt(111) b Pt(110) in a nonadsorbing electrolyte such as HClO 4 [7,8].…”

Computational Screening for Developing Optimal Intermetallic Transition Metal Pt-Based ORR Catalysts at the Predictive Volcano Peak

“…Specific compositions of MN in Pt-skin Pt 3 (MN) 1 , which fall the closest to this predicted volcano maximum, include on the left leg, Os 2 Ir 2 , Ru 2 Cu 2 , Os 2 Ru 2 , Co 2 Pd 2 , Ru 2 Rh 2 , Ru 2 Pd 2 , and Ir 2 Pd 2 and on the right leg, Ru 2 Ir 2 , Os 2 Pd 2 , Ru 4 , Rh 2 Ir 2 , Rh 2 Ni 2 , Ni 4 , and then the base-metal ternary intermetallics previously reported . Many of these combinations of Os, Pd, Cu, and Rh compositions are showing performances similar to or better than those recently reported for bimetallic or ternary Pt-based systems. ,− ,,− We note that due to limitations of the computational model, calculation accuracy, and cutoff criteria, values within ∼0.03 eV for the descriptor Δ E ads O* should be treated as identical.…”

Composition-Tunable PtCu Alloy Nanowires and Electrocatalytic Synergy for Methanol Oxidation Reaction

“…The enhanced electrocatalytic performance is likely linked to the increased stability of the NW structure. This likely contributes to the increased resistance of the NWs to dissolution, aggregation, or Ostwald ripening in comparison with Pt/C catalyst in the acidic electrolyte, as suggested earlier. , …”

“…This likely contributes to the increased resistance of the NWs to dissolution, aggregation, or Ostwald ripening in comparison with Pt/C catalyst in the acidic electrolyte, as suggested earlier. 14,47 In comparison with the data for the above PtCu NWs with low Pt%, Pt 70 Cu 30 alloy NWs (Figure S6 A) exhibited a mass activity of 322 mA mg −1 , which is slightly higher than that of commercial Pt/C catalyst (293 mA mg −1 ) and much lower than that of pure Pt NWs(483 mA mg −1 ). The stability of Pt 70 Cu 30 alloy NWs (Figure S6 B) was also worse than commercial Pt/C catalyst.…”