Environmentally benign halloysite clay nanotubes as alternative catalyst to metal nanoparticles in H2 production from methanolysis of sodium borohydride

Here, for the first time a natural clay, halloysite nanotubes (HNTs) was used as catalyst in H-2 generation from methanolysis of sodium borohydride (NaBH4). The natural HTNs were modified with (3-aminopropyl)triethoxysilane (APTES) and then threated with HCI to obtain mod-HNTs (HNTs-NH2.HCI) as natural catalysts. The catalytic activity of mod-HNTs was found to be comparable for the very well-known metal nanoparticle catalysts used for the same purpose in the literature. Moreover, the activation energy, enthalpy and entropy are calculated 30.41 kJ center dot mol(-1), 27.93 kj center dot mol(-1), and -16327 J center dot mol(-1)K(-1), respectively and are also comparable with metal nanoparticle catalysts that are used in H2 generation reactions. Interestingly, the mod-HNT catalysts showed greater reusability with catalytic activity (91%) after 10th usage having 100% conversion at each time. Additionally, H-2 generation rate of about 220.5 mLmin(-1)g(-1) Icatalyst which is comparable to most of the reported good catalyst up to date. (C) 2016 Elsevier B.V. All rights reserved.