Hydrogen generation via NaBH4 hydrolysis over cobalt-modified niobium oxide catalysts

Author(s)

Santos, Fabiana L. ; Giroto, Amanda S. ; Torres, Juliana A. ; Oliveira, Anna V. P. S. ; Santos, Vinicius M. F. e ; Nogueira, Andre E.

• Document type: Journal article
• Source: INTERNATIONAL JOURNAL OF HYDROGEN ENERGY; v. 92, p. 11-pg., 2024-10-23.

Abstract

The increasing concentration of CO2 in the atmosphere, primarily driven by fossil fuel combustion, is a major contributor to global warming and one of the most pressing environmental challenges of the 21st century. In response, the development of sustainable energy technologies, such as hydrogen (H2) production, has become crucial in the global transition to a low-carbon economy. In this study, we explored the catalytic activity of cobalt-modified niobium-based catalysts for hydrogen generation through the hydrolysis of NaBH4. The catalysts were characterized using XRD, FTIR, XPS, SEM-EDX, and N2 adsorption-desorption. XRD analysis revealed that the synthesized Nb2O5 (Nb2O5 Synt.) and Nb2O5/Co (Nb2O5/Co Synt.) exhibited amorphous structures, while the commercial Nb2O5 (Nb2O5 Com.) and its Co-modified composite displayed orthorhombic phases. The Nb2O5/Co Synt. catalyst achieved a surface area of 33.1 m2/g, significantly surpassing that of the commercial Nb2O5. The Nb2O5/Co Synt. catalyst exhibited superior catalytic activity, yielding 250 mL of hydrogen in 60 min, in contrast to other catalysts that showed no activity under identical conditions. This enhanced activity was attributed to the presence of surface hydroxyl groups and metallic Co nanoparticles, following the Langmuir-Hinshelwood bimolecular mechanism. Temperature was identified as a critical factor in the H2 production rate, with a calculated activation energy of 11.37 kJ/mol. Moreover, the Nb2O5/Co Synt. catalyst demonstrated excellent reusability, maintaining stable performance after multiple reaction cycles, highlighting its potential for sustainable hydrogen production. (AU)

• FAPESP's process: 23/17686-4 - Development of multifunctional niobium catalysts: advances in CO2 conversion and H2 generation
• Grantee: André Esteves Nogueira
• Support Opportunities: Regular Research Grants