RESEARCH

Electrocatalysis

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Ru oxides and substituted Ru oxides

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Longsheng Cao, Fernando A. Soto, Dan Li, Tao Deng, Enyuan Hu, Xiner Lu, David A. Cullen, Michael J. Zachman, Nico Eidson, Xiao-Qing Yang, Kai He, Perla B. Balbuena, and Chunsheng Wang, Pd-Ru pair on Pt surface for promoting hydrogen oxidation and evolution in alkaline media,”  Communications, 15 (1), 7245 (2024).

Hydrogen oxidation reaction in alkaline media is critical for alkaline fuel cells and electrochemical ammonia compressors. The slow hydrogen oxidation reaction in alkaline electrolytes requires large amounts of scarce and expensive platinum catalysts. While transition metal decoration can enhance Pt catalysts’ activity, it often reduces the electrochemical active surface area, limiting the improvement in Pt mass activity… View more

Francisco Ospina-Acevedo, Luis A. Albiter, Kathleen O. Bailey, José Fernando Godínez-Salomón, Christopher P. Rhodes, and Perla B. Balbuena, Catalytic Activity and Electrochemical Stability of Ru1-xMxO2 (M = Zr, Nb, Ta): Computational and Experimental Study of the Oxygen Evolution Reaction,” ACS Appl. Materials & Interfaces, 2024, 16, 13, 16373–16398.

We use computations and experiments to determine the effect of substituting zirconium, niobium, and tantalum within rutile RuO2 on the structure, oxygen evolution reaction (OER) mechanism and activity, and electrochemical stability. Calculated electronic structures altered by Zr, Nb, and Ta show surface regions of electron density depletion and accumulation, along with anisotropic lattice parameter shifts dependent on the substitution site… View more 

Jose Fernando Godínez-Salomón, Francisco Ospina-Acevedo, Luis A. Albiter, Kathleen O. Bailey, Zachary G. Naymik, Rubén Mendoza-Cruz, Perla B. Balbuena, and Christopher P. Rhodes, Titanium Substitution Effects on Structure, Activity, and Stability of Nanoscale Ruthenium Oxide Oxygen Evolution Electrocatalysts: Experimental and Computational Study,” ACS Appl. Nano Materials, 5, 8, 11752–11775, (2022).

Proton-exchange membrane water electrolyzers produce hydrogen from water and electricity and can be powered using renewable energy; however, the high overpotential, high cost, and limited supply of the oxygen evolution reaction (OER) electrocatalyst are key factors that hinder wide-scale adoption. Ruthenium oxide (RuO2) has a lower overpotential, lower cost, and higher global supply compared with iridium oxide (IrO2), but RuO2 is less stable than IrO2. As an approach to improve the catalytic stability, we report the effect of titanium substitution at… View more 

Luis E. Camacho-Forero, Fernando Godínez-Salomón, Guadalupe Ramos-Sánchez, Christopher P. Rhodes, and Perla B. Balbuena, Theoretical and Experimental Study of the Effects of Cobalt and Nickel Doping within IrO2 on the Acidic Oxygen Evolution Reaction,” J. of Catalysis, 408, 64-80, (2022).

The effect of Ni and Co doping within IrO2 on the structure and oxygen evolution reaction (OER) was studied using integrated theory and experiments. Density Functional Theory (DFT) calculations show that the metal dopant influences the distribution of electronic charge and affects the thermodynamics and kinetics aspects of the OER when compared with undoped IrO2. Using DFT, multiple different reaction pathways were evaluated for… View more 

Dry reforming of methane 

Supareak Praserthdam, Siriwimol Somdee, Meena Rittiruam, and Perla B. Balbuena,  Computational Study of the Evolution of Ni-Based Catalysts during the Dry Reforming of Methane,” Energy & Fuels, 34, 4, 4855-4864, (2020).

We evaluated the Ni-based catalyst surface properties during possible transformation pathways between its metallic, oxide, and carbide phases, causing catalytic deactivation. The study uses density functional theory (DFT) calculations to determine thermodynamics and reaction mechanisms of elementary reactions, and the ratings concept is introduced previously as an evaluation tool for the dry reforming reaction of methane (DRR) catalyst…. View more 

F. A. Ospina-Acevedo, S. Perez Beltran, P. B. Balbuena, Mechanisms of Alumina Growth via Atomic Layer Deposition on Nickel Oxide and Metallic Nickel Surfaces,” Phys. Chem. Chem. Phys., 21, 24543-24553, (2019).

We aim at elucidating the mechanism of the trimethyl aluminum (TMA) decomposition on oxidized nickel (NiO) and metallic nickel (Ni) facets in the absence of a source of hydroxyl groups. This TMA decomposition mechanism constitutes the earliest stage of growth of Al2O3 coatings with the atomic layer decomposition (ALD) method, which stabilizes nickel catalysts in energy-intensive processes such as the dry reforming of methane… View more