Catalytic Co-Mo Alloys for Hydrogen Generation
Graduate Category: Engineering and Technology Degree Seeking: MS Abstract ID #1734
Catalytic Co-Mo Alloys for Hydrogen Generation Cheng Wang and Elizabeth J. Podlaha Opportunity
Approach
• Introduction
1. Electrodeposition
Molybdenum alloys are recognized for their outstanding catalytic ability toward the hydrogen evolution reaction needed to split water for the production of clean hydrogen. High hydrogen generation rates have been found with Co-Mo alloy films that are either sputtered1 or electrodeposited.2-3 In this work, boric acid, 2-butyne, 1,4-diol (BD) and TiO2 are used as additives, to explore how the additives and different deposition conditions affect the deposit composition, thus altering the water catalysis. Characterization of the catalytic effect in a basic electrolyte is presented.
Composition of solutions Electrolytes
Insulator
Pt anode Rotating Hull Cell for surveying the applied current density
2.1 Characterize Composition
2.2 Characterize HER
Composition determined by XRF
• Objective Explore the hydrogen evolution reaction (HER) kinetics of Co-Mo alloys electrodeposited using a novel electrolyte containing BD and titania nanoparticles.
Pt
Reference • HER testing in electrode, 1 M NaOH Ag/AgCl • Linear sweep voltammetry CO-Mo alloy
Impact
Data/Results 1. Composition Characterization • Deposit Mo composition increased with electrolyte concentration in a non-linear manner. • Mo content decreased with applied current density when the electrolyte concentration of molybdate was low, but exhibited a parabolic behavior, having a maximum at the higher electrolyte concentrations.
2. HER Characterization
TiO2 Sodium Cobalt nano BD Solution Molybdate Sulfate Particle (mM) (M) (M) (g/L) 1 0.005 0.1 0 2.5 2 0.015 0.1 0 2.5 3 0.045 0.1 0 2.5 4 0.045 0.1 12.5 2.5
Cu (WE)
In the kinetic regime the cathodic HER is governed by the Tafel equation: i=io*exp((− )/ ( − )) • io is proportional to the Mo content in the deposition. The higher the Mo content of the electrode, the greater the catalytic capacity towards HER. The maximum value of io is 1.92E-03 A/cm2.
• Catalytic hydrogen evolution was observed and films with molybdenum content around 40 wt% have been found to have large catalytic rates. • The deposit composition was affected by the amount of molybdate in solution and the current density. • The effect of adding titania nanoparticles in solution is undetermined because of it’s low content in the deposition.
References 1. T. Aihara, A. Kawashima, E. Akiyama, H. Habazaki, K. Asami, and K. Hashimoto, Mater. Trans., JIM, 39, 1017 (1998) 2. E. Navarro-Flores, Z. Chong and S. Omanovic, J. Mol. Catal. A: Chem., 226 (2005). 3. P. R. Zabinski, H. Nemoto S. Meguro, K. Asami, and K. Hashimoto, J. Electrochem. Soc., 150 (10)C717-C722(2003).
• The titania nanoparticles added in the fourth solution did not significantly improve nor degrade the deposition’s catalytic performance, most likely due to the low amount of nanoparticles captured in the deposition (
Catalytic Co-Mo Alloys for Hydrogen Generation Cheng Wang and Elizabeth J. Podlaha Opportunity
Approach
• Introduction
1. Electrodeposition
Molybdenum alloys are recognized for their outstanding catalytic ability toward the hydrogen evolution reaction needed to split water for the production of clean hydrogen. High hydrogen generation rates have been found with Co-Mo alloy films that are either sputtered1 or electrodeposited.2-3 In this work, boric acid, 2-butyne, 1,4-diol (BD) and TiO2 are used as additives, to explore how the additives and different deposition conditions affect the deposit composition, thus altering the water catalysis. Characterization of the catalytic effect in a basic electrolyte is presented.
Composition of solutions Electrolytes
Insulator
Pt anode Rotating Hull Cell for surveying the applied current density
2.1 Characterize Composition
2.2 Characterize HER
Composition determined by XRF
• Objective Explore the hydrogen evolution reaction (HER) kinetics of Co-Mo alloys electrodeposited using a novel electrolyte containing BD and titania nanoparticles.
Pt
Reference • HER testing in electrode, 1 M NaOH Ag/AgCl • Linear sweep voltammetry CO-Mo alloy
Impact
Data/Results 1. Composition Characterization • Deposit Mo composition increased with electrolyte concentration in a non-linear manner. • Mo content decreased with applied current density when the electrolyte concentration of molybdate was low, but exhibited a parabolic behavior, having a maximum at the higher electrolyte concentrations.
2. HER Characterization
TiO2 Sodium Cobalt nano BD Solution Molybdate Sulfate Particle (mM) (M) (M) (g/L) 1 0.005 0.1 0 2.5 2 0.015 0.1 0 2.5 3 0.045 0.1 0 2.5 4 0.045 0.1 12.5 2.5
Cu (WE)
In the kinetic regime the cathodic HER is governed by the Tafel equation: i=io*exp((− )/ ( − )) • io is proportional to the Mo content in the deposition. The higher the Mo content of the electrode, the greater the catalytic capacity towards HER. The maximum value of io is 1.92E-03 A/cm2.
• Catalytic hydrogen evolution was observed and films with molybdenum content around 40 wt% have been found to have large catalytic rates. • The deposit composition was affected by the amount of molybdate in solution and the current density. • The effect of adding titania nanoparticles in solution is undetermined because of it’s low content in the deposition.
References 1. T. Aihara, A. Kawashima, E. Akiyama, H. Habazaki, K. Asami, and K. Hashimoto, Mater. Trans., JIM, 39, 1017 (1998) 2. E. Navarro-Flores, Z. Chong and S. Omanovic, J. Mol. Catal. A: Chem., 226 (2005). 3. P. R. Zabinski, H. Nemoto S. Meguro, K. Asami, and K. Hashimoto, J. Electrochem. Soc., 150 (10)C717-C722(2003).
• The titania nanoparticles added in the fourth solution did not significantly improve nor degrade the deposition’s catalytic performance, most likely due to the low amount of nanoparticles captured in the deposition (
