M Brooks Robert, Maafa Ibrahim M, M Al-Enizi Abdullah, M El-Halwany M, Ubaidullah Mohd, Yousef Ayman
Department of Civil and Environmental Engineering, Temple University, 1947 N. 12th Street, Philadelphia, PA 19122, USA.
Department of Chemical Engineering, Faculty of Engineering, Jazan University, Jazan 45142, Saudi Arabia.
Nanomaterials (Basel). 2019 Jul 28;9(8):1082. doi: 10.3390/nano9081082.
In this study, we report on the fabrication and utilization of NiCr alloy nanoparticles (NPs)-decorated carbon nanofibers (CNFs) as efficient and competent non-precious catalysts for the hydrolytic dehydrogenation of ammonia borane (AB) at 25 ± 2 °C. The introduced NFs have been fabricated in one step using a high-temperature thermal decomposition of the prepared electrospun nanofiber mats (nickel acetate tetrahydrate, chromium acetate dimer, and polyvinyl alcohol) in an inert atmosphere. The chemical composition of the NFs with different proportions of NiCr (x = 0.0, 0.1, 0.15, 0.2, 0.25, 0.3) was established via standard characterization techniques. These techniques proved the formation of disorder CrNi alloy and carbon for all the formulations. The as-synthesized composite NFs exhibited a higher catalytic performance for AB dehydrogenation than that of Cr-free Ni-CNFs. Among all the formulations, the sample composed of 15% Cr shows the best catalytic performance, as more H was released in less time. Furthermore, it shows good stability, as it is recyclable with little decline in the catalytic activity after six cycles. It also demonstrates the activation energy, entropy (ΔS), and enthalpy (ΔH) with 37.6 kJ/mole, 0.094 kJ/mole, and 35.03 kJ/mole, respectively. Accordingly, the introduced catalyst has a lower price with higher performance encouraging a practical sustainable H energy application from the chemical hydrogen storage materials.
在本研究中,我们报道了镍铬合金纳米颗粒(NPs)修饰的碳纳米纤维(CNFs)的制备及其作为高效且合格的非贵金属催化剂在25±2℃下催化氨硼烷(AB)水解脱氢的应用。所制备的纳米纤维是通过在惰性气氛中对制备好的电纺纳米纤维毡(四水合醋酸镍、二聚醋酸铬和聚乙烯醇)进行高温热分解一步制备而成。通过标准表征技术确定了不同镍铬比例(x = 0.0、0.1、0.15、0.2、0.25、0.3)的纳米纤维的化学成分。这些技术证明了所有配方中均形成了无序的CrNi合金和碳。所合成的复合纳米纤维对AB脱氢表现出比无铬镍 - 碳纳米纤维更高的催化性能。在所有配方中,由15%铬组成的样品表现出最佳的催化性能,因为在更短的时间内释放出了更多的氢气。此外,它还具有良好的稳定性,因为它可以循环使用,经过六个循环后催化活性几乎没有下降。它还分别展示了活化能、熵(ΔS)和焓(ΔH),分别为37.6 kJ/摩尔、0.094 kJ/摩尔和35.03 kJ/摩尔。因此,所引入的催化剂价格较低且性能较高,这鼓励了从化学储氢材料中实现实际可持续的氢能应用。