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    Tungsten(VI) oxide-supported nickel/silver nanoparticles for photocatalytic hydrogen evolution from ammonia-borane
    (Pergamon-Elsevier Science Ltd, 2024) Cetin, Mustafa Berat; Top, Tuba; Yurderi, Mehmet; Zahmaknran, Mehmet; Rakap, Murat
    Developing efficient catalysts for hydrogen (H 2 ) evolution from ammonia-borane (AB, NH 3 BH 3 ) is crucial for fuel cell applications. Photocatalytic hydrolysis of AB by heterogeneous catalysts under light irradiation has attracted attention as an effective technique for H 2 evolution. Here, we report an impregnation-reduction method to prepare the tungsten(VI) oxide-supported nickel/silver nanoparticles (denoted as NiAg/WO 3 ) and their characterization by advanced tools such as ICP-OES, PXRD, SEM, TEM, and XPS. The initial turnover frequency (TOF), activation energy ( E a # ), activation enthalpy ( Delta H # ), and activation entropy ( Delta S # ) values of NiAg/WO 3 nanoparticles in H 2 evolution from AB under visible light irradiation are calculated as 56.6 molH 2 & sdot; molNi 0.27 Ag 0.73 - 1 & sdot; min -1 , 52.14 kJ & sdot; mol -1 , 47.78 kJ & sdot; mol -1 , and -91.62 J & sdot; mol -1 & sdot; K -1 , respectively. These findings are especially significant for a feasible application of AB in H 2 fuel cells.
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    ZIF-8 decorated FeMo nanoparticles: H2 Production from the catalytic hydrolysis of ammonia-borane
    (Wiley, 2024) Yilmaz, Can; Yildirim, Huseyin Ali; Top, Tuba; Yurderi, Mehmet; Zahmakiran, Mehmet
    Ammonia-Borane (AB) is considered a promising solid hydrogen storage material due to its high hydrogen content (19.6 wt%) and its use for safe hydrogen transport. The most effective way to produce H-2 from AB is to perform the hydrolysis reaction in the presence of a suitable catalyst. In this study, Fe0.2Mo0.8/ZIF-8 nanocatalyst was synthesized in two steps: (i) synthesis by following the colloidal synthesis technique by thermal decomposition of Mo(CO)(6) and Fe(acac)(3) in the presence of OM and ODE at high temperatures, and (ii) the resulting colloidal Fe0.2Mo0.8 NPs were decorated into ZIF-8. The as-prepared Fe0.2Mo0.8/ZIF-8 catalyst was identified using advanced characterization techniques such as ICP-OES, P-XRD, SEM, SEM-EDX, TEM, TEM-EDX, XPS, and BET. The catalytic activities of the Fe0.2Mo0.8/ZIF-8 catalyst in the hydrolysis of AB were investigated in different parameters (temperature, catalyst [Fe0.2Mo0.8] and substrate [H3NBH3] concentration, and recyclability). The results show that high crystallinity Fe0.2Mo0.8 NPs with a uniform 1.31 +/- 0.13 nm distribution were formed on the ZIF-8 surface. Fe0.2Mo0.8/ZIF-8 catalyst provides a maximum H-2 generation rate of 184.2 mLH(2) (g catalyst)(-1) (min)(-1) at 343 K. This uniquely cost-effective, active and durable Fe0.2Mo0.8/ZIF-8 catalyst has strong potential for H-2-based fuel cell (PEM: Proton Exchange Membrane) applications where AB is a suitable H-2 carrier.