Anode Materials for Low-Temperature Fuel Cells: A Density Functional Theory Study

doi:10.1006/jcat.2000.3136

Journal of Catalysis

Volume 199, Issue 1, 1 April 2001, Pages 123-131

https://doi.org/10.1006/jcat.2000.3136 Get rights and content

Abstract

Based on density functional calculations, we discuss the effect of alloying Pt with other metals for use as anode catalyst materials in low-temperature fuel cells. We discuss why a few parts per million of CO in the H₂ fuel can poison Pt surfaces and how this problem can be alleviated by alloying, and an extensive data base of the effect of alloying on the reactivity that includes all binary combinations of the transition metals to the right in the periodic table is given. We also discuss the effect of surface segregation and give a calculated data base of segregation energies of binary transition metal alloys. Based on extensive Monte Carlo simulations we show that while the adsorbate-free surface of a Ru_0.5Pt_0.5 alloy has no Ru in the first layer, the presence of CO can move some Ru to the surface, but all these Ru atoms are covered by CO.

References (36)

L. Liu et al.
Elec. Acta
(1998)
J.C. Davies et al.
Elec. Acta
(1998)
E.G. Seebauer et al.
Surf. Sci.
(1986)
B. Hammer et al.
Adv. Catal.
(2000)
A. Ruban
J. Mol. Catal. A
(1997)
A.V. Ruban et al.
Compt. Mater. Sci.
(1999)
R.J. Koestner et al.
Surf. Sci.
(1981)
P. Hollins et al.
Surf. Sci.
(1979)
J.C. Bertolini et al.
Surf. Sci.
(1983)
R. Linke et al.
Surf. Sci.
(1994)

C. Becker et al.

Surf. Sci.

(1994)

G. Hoogers et al.

Catttech

(2000)

M.P. Hogarth et al.

Platinum Metals Rev.

(1996)

H.A. Gasteiger et al.

J. Phys. Chem.

(1994)

M. Watanabe et al.

Electrochemistry

(1999)

H.F. Oetjen et al.

J. Electrochem. Soc.

(1996)

F.Buatier de Mongenot et al.

Surf. Sci.

(1998)

Cited by (330)

Advanced Ru/Ti<inf>4</inf>O<inf>7</inf> catalyst for Tolerating CO and H<inf>2</inf>S poisoning to hydrogen oxidation reaction
2024, International Journal of Hydrogen Energy
CO and H₂S poisoning of Pt-based catalysts for hydrogen oxidation reaction (HOR) stands as one of the long-standing hindrances to the widespread commercialization of proton exchange membrane fuel cells. In this paper, a Ru/Ti₄O₇ catalyst is successfully synthesized by the microwave-thermal method. This Ru/Ti₄O₇ catalyst shows a much higher noble metal mass activity than those of commercial PtRu/C and conventional Ru/C catalysts. The performance of the Ru/Ti₄O₇ catalyst under the exist of CO or H₂S shows insignificant current decay, which is far superior to commercial PtRu/C and Pt/C catalysts. In this Ru/Ti₄O₇ catalyst, the electron transfer between Ru and Ti to form d-p orbital hybridization is considered to be responsible for the favorable catalytic HOR performance and the corresponding CO and H₂S tolerance. The interaction mechanism formed by electron transfer may open a promising way for the subsequent development of anti-poisoning catalysts for PEM fuel cell hydrogen oxidation reaction.
Study of the photocatalytic reforming and oxidation of Glycerol over Ag–Pd/TiO<inf>2</inf>
2024, International Journal of Hydrogen Energy
The photocatalytic reaction of glycerol was conducted over 0.1 at. % Ag – 0.3 at.% Pd/TiO₂ catalyst in order to monitor the switch over between the photo-reforming to hydrogen and CO₂ and photo-oxidation to H₂O and CO₂. This alloy of Ag–Pd has shown to be more active than Pd for hydrogen ion reduction previously. Up to a partial pressure of about 0.2 atm. of molecular oxygen the rates of hydrogen production were mostly unaffected. There seems to be a threshold for the effect of O₂ on the inhibition of hydrogen production. This is found when the ratio of dissolved molecular oxygen to surface Ti cations is about 2. Also, the order of reaction with respect to P_O2 was found to be −2. Hydrogen production was found to be largely insensitive to glycerol concentrations (above 0.05 vol %) as expected from a zero order reaction kinetics in the liquid phase, where the rate is determined by surface coverage. The considerable amounts of dissolved CO₂ found indicate that monitoring gas phase CO₂ is not a true measurement of the photo-reaction rates. The dissolved CO₂ concentration was 15–20% of the gas phase concentration of CO₂ at any reaction time investigated. The fast decrease of the pH of the aqueous solution within the first 30 min points to the build up of oxidation products of glycerol. Liquid phase analysis showed the presence of formaldehyde, hydroxy acetone and ethylene glycol as the main reaction products. At high glycerol concentration the main product in the liquid phase was hydroxy acetone while at low concentrations it was formaldehyde. At low glycerol concentrations, the rise of formaldehyde concertation in the liquid phase with time was concomitant with hydrogen production, its decay with time, however, was not accompanied by further increase in hydrogen production. This is most likely because of the competition between decomposition in the presence of water (to H₂ and CO₂) and oxidation (to formates).
Rational design of one-dimensional cobalt-related oxygen electrocatalysts toward high-performance zinc-air batteries
2023, Coordination Chemistry Reviews
Zinc-air batteries (ZABs) have been widely investigated in fields such as energy, materials, and devices due to their green and efficient characteristics. Nonetheless, the electrochemical performance of ZABs is limited by the ability of the cathode to catalyze oxygen reactions. Pt-based and Ir or Ru-based precious metals have been successfully used as catalysts in the market. Due to the scarce resources and high costs of these precious metals, non-precious metal catalysts have been able to conduct research. Among them, cobalt-related transition metal catalysts are considered one of the most promising candidates due to their low cost and high activity. However, poor conductivity and cyclic stability limit its commercial application. Nano design is extremely important in improving catalytic performance, especially one-dimensional (1D) morphology control has been confirmed to be an effective modification method for improving electrochemical performance. In this review, the principles for designing 1D cobalt-related oxygen electrocatalysts toward high-performance ZABs, such as Co-immobilized carbon composites, cobalt oxides, cobalt sulfides, and cobalt phosphides are reviewed. Next, the strategies aiming at improving the electrocatalytic activity and stability are summarized. At last, the challenges and perspectives of cobalt-related oxygen electrocatalysts for ZABs are discussed. This review can offer insights into the targeted optimization of 1D cobalt-related oxygen electrocatalysts, which can be expected to shed light on the future development of high-performance ZABs.
Origin of enhanced toluene hydrogenation by Pt–Ru catalysts for an efficient liquid organic hydrogen carrier
2023, International Journal of Hydrogen Energy
Novel catalysts for efficient formation of liquid organic hydrogen carriers (LOHCs) used in hydrogen storage and transport show great promise. Although Pt–Ru alloys have exhibited catalytic activities superior to those of Pt in the hydrogenation of toluene to methylcyclohexane, the origins are still unclear. Herein, we use density functional theory (DFT) to examine the mechanisms for toluene hydrogenation on Pt and various Pt–Ru bimetallic catalysts. The core@shell-type Ru@Pt(111) shows more thermodynamically and kinetically favored hydrogenation of toluene than pure Pt or Pt–Ru ordered structures. The origin of the improved catalytic activity on Ru@Pt(111) is examined by separating the strain and ligand effects between the core and shell layers. The ligand effect lowers the d-band center more pronouncedly; moreover, the favorable charge gain on the surface lowers the binding energies of reaction intermediates as well as the activation energies for each hydrogenation step. This work provides insight into the design of novel catalysts providing LOHCs for efficient hydrogen storage.
Surface engineered PdNFe<inf>3</inf> intermetallic electrocatalyst for boosting oxygen reduction in alkaline media
2023, Applied Catalysis B: Environmental
Surface engineering has been identified as an effective way to maximize the utilization of noble atoms and facilitate the oxygen reduction reaction. However, a cost-effective and highly durable platform for tailoring the electrocatalytic activity, is still absent. Herein, we demonstrate a new and promising catalytic material of antiperovskite-typed PdNFe₃ and construct a high performance PdNFe₃ @Pd catalyst with atomic layers of strained Pd shell. The PdNFe₃ @Pd/C catalyst presents a high mass activity (MA) of 1.14 A mg⁻¹_Pd at 0.9 V, which is 9 and 6 times higher than those of the Pt/C and Pd/C, respectively. More importantly, the excellent performance of PdNFe₃ @Pd/C was also verified in anion-exchange membrane fuel cells and rechargeable Zn−air batteries. Density functional theory calculations reveal that the strain effect aroused by the lattice mismatch between PdNFe₃ core and Pd shell contributes to the enhanced ORR performance by optimizing the binding strength of oxygen intermediates on Pd.
Alloy-free amorphous Pt–B–P/C electrocatalyst for enhanced methanol electro-oxidation
2021, International Journal of Hydrogen Energy
This study reports the first known demonstration of amorphous Pt–B–P/C achieved via electroless reduction without the need for additional unstable transition metals. The amorphous structure was induced by simultaneous dual doping of both B and P by electroless reduction of Pt ion solution using a simple and facile process at ambient conditions. Amorphous Pt–B–P/C exhibited superior specific, mass activity compared to both commercial PtRu/C and crystalline Pt–B–P/C. Durability and CO poisoning resistance were also found to be better. XPS and annealing results suggest that synergistic effect of both doping and amorphous structure of Pt–B–P/C led to its overall enhanced catalytic performance.

View all citing articles on Scopus

¹: To whom correspondence should be addressed. Fax: (+45) 45 93 23 99. E-mail: [email protected].

View full text

Regular ArticleAnode Materials for Low-Temperature Fuel Cells: A Density Functional Theory Study

Abstract

Elec. Acta

Elec. Acta

Surf. Sci.

Adv. Catal.

J. Mol. Catal. A

Compt. Mater. Sci.

Surf. Sci.

Surf. Sci.

Surf. Sci.

Surf. Sci.

Surf. Sci.

Catttech

Platinum Metals Rev.

J. Phys. Chem.

Electrochemistry

J. Electrochem. Soc.

Surf. Sci.

Regular Article
Anode Materials for Low-Temperature Fuel Cells: A Density Functional Theory Study