Three eagles with one arrow: Simultaneous production of hydrogen, aluminum ethoxide, and supported metal catalysts via efficient and facile reaction between aluminum and ethanol

Complex preparation, risky storage, and expensive transportation are hindering the application of hydrogen (H2) energy. To overcome these, a simple, cost-effective, and zero CO2-emission method is urgently needed. This study for the first time showed that the aluminum-ethanol (Al-ethanol) reaction without the need of complex pre-treatment can produce simultaneously hydrogen, aluminum ethoxide [Al(EtO)3], and supported metallic nanoparticle (NP) catalyst. Fe (3.6 nm), Co (3.5 nm), Ni (2.9 nm), and Cu (3.5 nm) NPs, in-situ generated by the galvanic replacement reaction between aluminum and metal ions, provided the catalytically active sites for the Al-ethanol reaction, effectively enhancing H2 and Al(EtO)3 formation. Consequently, the Al-ethanol reaction catalyzed by the Ni NPs with the smallest average size at 50 °C led to the formation of hydrogen at a high rate of 109 mL-H2·min−1·g-Al−1. Density functional theory (DFT) calculations suggested that the in-situ generated Ni NPs had charge transfer with ethanol and aluminum, which significantly enhanced the ethanol adsorbing capability onto the aluminum. Moreover, recovery of high value-added Al(EtO)3 and utilization of supported metallic catalyst could additionally benefit the practical application of the Al-ethanol reaction. With the proposed “three eagles with one arrow” strategy, simultaneous generation of H2, Al(EtO)3 and supported metallic catalyst could be readily realized in a more straightforward, scalable and economical way.