Near-Thermoneutral Hydrogen Adsorption on TPO-graphene: A DFT Study for Acidic HER

Near-Thermoneutral Hydrogen Adsorption on TPO-graphene: A DFT Study for Acidic HER

• Autor
• Juan Rafael Gomez Quispe
• Co-autores
• Pedro Alves da Silva Autreto
• Resumo

•  

  Tetra-penta-octagonal graphene (TPO-graphene) is a theoretically proposed two-dimensional carbon allotrope composed of tetragonal, pentagonal, and octagonal rings [1]. Previous studies have shown that this material is structurally stable, metallic, and porous, making it an appealing platform for catalytic applications  [1,2]. In this work, density functional theory (DFT) calculations were employed to investigate the potential of TPO-graphene as an electrocatalyst for the hydrogen evolution reaction (HER) under acidic conditions, where efficient proton adsorption and reduction are essential for catalytic performance. The catalytic performance was evaluated using the Gibbs free energy of hydrogen adsorption (?G_H^*), a widely accepted descriptor for HER activity. In carbon-based catalysts, optimal HER behavior is generally associated with adsorption free energies close to the thermoneutral value, where hydrogen binding is neither too weak nor too strong. Recent theoretical studies on related carbon allotropes have shown that non-hexagonal ring arrangements, curvature, and local structural asymmetry can effectively tune hydrogen adsorption and improve HER activity [2,3]. Our results show that TPO-graphene exhibits a hydrogen adsorption free energy of ?G_H^* = -0.09 eV, which is close to the ideal thermoneutral value. This result indicates a favorable balance between hydrogen adsorption and desorption, suggesting that TPO-graphene can provide active sites with suitable binding strength for efficient HER. These findings establish TPO-graphene as a promising candidate for acidic HER and provide theoretical guidance for the rational design of efficient metal-free carbon electrocatalysts.

  Acknowledgments

  The authors thank the Coordination for the Improvement of Higher Education Personnel CAPES for funding and the UFABC Computation Multiuser Center (CCM) for the computational resources provided.

  References:

  [1] D. Bhattacharya and D. Jana, Phys. Chem. Chem. Phys. 21, 24758 (2019).

  [2] J. H. Seok, H. N. Manh, et al., Nano Energy 147, 111588 (2026).

  [3] J. R. Gomez Quispe, F. G. Ordinola Sanchez, et al., ACS Omega 11, 5211 (2026).

• Palavras-chave
• 2D carbon allotropes, HER, DFT
• Modalidade
• Comunicação oral
• Área Temática
• Materiais Avançados