TEMPERATURE-INDUCED CHANGES IN PORE STRUCTURE AND CATALYTIC PERFORMANCE OF ALUMINUM OXIDE MEMBRANES

Anvar Khamidov, Farhodjon Hoshimov, Khakimjan Butanov, Shavkat Mamatkulov, Bahrom Umarov, Dong Fang, Mika Sillanpää, Luca Pasquini, Philippe Knauth, Olim Ruzimuradov

Abstract

In this study, we synthesized nanostructured anodic aluminum oxide (AAO) membranes through the two-step anodization process using oxalic acid as the electrolyte. The main objective was to investigate how the electrolyte temperature influences the formation of pores in the AAO membranes. Key parameters, including pore diameter, interpore distance, thickness, and porosity, were measured and subjected to statistical analysis. The experimental results clearly demonstrated that under specified conditions involving temperatures at 5, 15 and 25 ºC, an oxalic acid concentration of 0.3 M, and applied voltage of 55 V, we achieved the successful fabrication of well-ordered nanoporous aluminum oxide membranes. The scanning electron microscopy (SEM) technique was used to examine both the surface morphology and cross-sectional views of the anodic membranes. Additionally, we explored the catalytic properties of nickel and molybdenum- impregnated AAO in the hydrogenation reaction of certain alkenes (C6-C8) across a range of temperatures. In the process of converting alkenes to alkanes, our research demonstrated that the Ni/AAO catalyst exhibited activity at 200 °C, while the Ni-Mo/AAO catalyst began to activate at around 250 °C.

https://doi.org/10.32737/2221-8688-2025-4-533-541