CuMOF@Faujasite nanocomposite as a novel catalyst for hydrogen production

Abstract

Energy production is one of the most crucial issues presently attracting global attention. In this work, a CuMOF@Faujasite nanocomposite was synthesized and utilized as a novel efficient catalyst for hydrogen production. The produced composite was first characterized using X‐ray diffraction (XRD), Fourier‐ transform infrared (FT‐IR), thermogravimetric analysis (TGA), and differential scanning calorimetry. Surface properties were analyzed via nitrogen adsorption–desorption isotherms. All characterization results revealed the formation of a pure and well‐defined crystalline phase, with a high specific surface area (SBET) of 286 m2/g (SBET of Faujasite is 35 m2/g). Moreover, the morphology and compositional analysis of the nanocomposite were assured through the scanning (SEM) and transmission (TEM) electron microscope and X‐ray photospectroscopy (XPS). SEM and TEM images revealed sponge‐like spheres that are related to Faujasite besides small spherical particles related to CuBDC MOF. XPS analysis revealed a low content of CuMOF in the nanocomposite. The catalytic activity of the nanocomposite was tested for the dehydrogenation of NaBH4. The impact of NaBH4 concentration, weight of the catalyst, and the reaction temperature on NaBH4 hydrolysis was investigated. A hydrogen generation rate (HGR) of 484 mLmin−1 g−1 at 30 °C was achieved using 50 mg of the catalyst and 0.05 mol/l of NaBH4 owing to the high specific area and the selective active sites for such hydrolytic reaction. The kinetic analysis of the activity data indicates the first‐order behavior at low concentrations of NaBH4. Furthermore, at concentrations ≥0.065 mol L−1, zero‐order kinetics was predominant. The time needed for completion of the hydrolysis reaction was found to be decreased (~20 min) by increasing the catalyst mass as well as NaBH4 concentration or even by elevating the reaction temperature (~4 min at 60 °C). The activation energy was estimated; it was found to be 70.5 KJ mol−1. Ultimately, our catalyst showed a reasonable rate of hydrogen production, as compared to others reported earlier.