ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Investigating the incubation time of the water splitting reaction between aluminum powder and water

Abolfazl Khezri, Shahram Raygan, and Ahmad Ali Amadeh

Department of Metallurgy and Materials Engineering, University of Tehran, Tehran, Iran

E-mail: khezri.abolfazl@ut.ac.ir

Received: 28 May 2025  Accepted: 20 November 2025

Abstract:

The increasing reliance on fossil fuels has prompted a search for sustainable energy alternatives. Hydrogen production via aluminum-water splitting reactions is emerging as a promising solution for this problem. However, the protective oxide layer on aluminum inhibits the reaction under ambient conditions. This study investigates the splitting reaction between aluminum powder and water, focusing on the incubation time and the transformations occurring in the oxide surface layer. Experimental analyses were conducted to assess the transformations of the alumina layer over various retention times in water at isothermal temperatures of 35 °C and 45 °C, utilizing techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier-transform infrared spectroscopy (FTIR/ATR). A mathematical model was developed to estimate the incubation time based on the quantitative changes in hydroxyl group concentrations. Results indicated that the incubation time of aluminum powder at isothermal temperatures of 45 °C and 35 °C, using the custom-built equipment, was 160 min and 3000 min, respectively. According to the proposed mathematical model, these values were 159.5 min and 3064 min, respectively, showing a relatively good consistency with the results obtained from experimental tests. The intensity of peaks corresponding to associated hydroxyl groups at wavenumbers 2897 cm⁻¹ and 2980 cm⁻¹ increased significantly with longer retention times in water, such that the intensity of peaks for the sample retained for 3 h in water at a temperature of 45 °C showed a 40% increase over the intensity for 1 h. Prolonged exposure to water enhances the formation of surface hydroxyl groups, facilitating the breakdown of the alumina layer and subsequent hydrogen release.

Keywords: Water splitting; Aluminum; Incubation time; Surface hydroxyl group

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-025-04538-y

Chemical Papers 80 (3) 2647–2659 (2026)