A high-performance hydrogen generation system: Hydrolysis of LiBH4-based materials catalyzed by transition metal chlorides. (August 2020)

• Record Type: Journal Article
• Authors: Chen, Kang; Ouyang, Liuzhang; Wang, Hui; Liu, Jiangwen; Shao, Huaiyu; Zhu, Min
• Is Part Of: Renewable energy. Volume 156(2020)
• Page Start: 655
• Page End: 664
• Publication Date: 2020-08
• Subjects: LiBH4 -- Hydrolysis -- Hydrogen generation -- Transition-metal chlorides -- Catalyst -- LiBH4·NH3; Renewable energy sources -- Periodicals; Power resources -- Periodicals; Énergies renouvelables -- Périodiques; Ressources énergétiques -- Périodiques; 333.794
• DOI: 10.1016/j.renene.2020.04.030
• Languages: English
• ISSNs: 0960-1481

Abstract

Abstract: Lithium borohydride (LiBH4 ) has received much attention due to its high hydrogen density of 18.5 wt%. However, in the hydrolytic process for hydrogen supply, the sluggish kinetics of LiBH4 and the agglomeration of by-product greatly limit its wide utilization. In this work, transition-metal chlorides (CoCl2, NiCl2, FeCl3 ) are firstly adopted to explore the hydrogen liberation behaviors of LiBH4 . The hydrolysis kinetics can be well-controlled by tuning the concentration of chlorides. Among the above chlorides, CoCl2 displays much faster reaction kinetics, delivering a hydrogen generation rate ranging from 421 to 41701 mL min −1 g −1 with a maximum conversion of 95.3%, much higher than the value of 225 mL min −1 g −1 H2 with Pt–LiCoO2 . The maximum gravimetric hydrogen density may reach 8.7 wt% at H2 O/LiBH4 = 2–6 mol/mol. Furthermore, NH3 is introduced to solve the issue of uncontrollable kinetics of LiBH4 by forming its ammoniates, where LiBH4 ·NH3 catalyzed by CoCl2 could stably release over 4350 mL g −1 H2 per unit weight of LiBH4 within 30 min at 40 °C, with a hydrogen density of ∼7.1 wt% and a hydrogen yield of 97.0%. Our approaches adopting non-noble metal chlorides are efficient and affordable for hydrogen supply to PEMFCs via hydrolysis of LiBH4 -based materials. Highlights: LiBH4 -based materials catalyzed by non-noble metal chlorides are investigated for the first time. The gravimetric hydrogen density of LiBH4 hydrolysis may reach 8.7 wt%. The hydrolysis kinetics of LiBH4 could be well-controlled by CoCl2 solution. The conversion yield of LiBH4 ·NH3 nearly reaches 97% with a gravimetric hydrogen density of ∼7.1 wt%. The catalytic effect of CoCl2 is better than NiCl2 or FeCl3 . .