Abstract
The present article constitutes an objective review and a constructive analysis of the main bibliographic results regarding the production of hydrogen using ultrasound. In spite of clear trends showing the efficiency of sonolysis for H-2 production, as compared to conventional techniques, reported by several authors, many debates are still opened regarding synergy of coupled processes, mathematical modeling, influencing parameters, and engineering design, allowing a concise assessment of the sonochemical or ultrasound-assisted production of hydrogen. We aim through this article to highlight the state of research in this field, evaluate their validity and limitations, and clarify future directions to explore in order to attain a macroscale production of hydrogen using ultrasound.