Ammonia borane nanofibers supported by poly(vinyl pyrrolidone) for dehydrogenation

Abstract

An effective strategy of utilizing electrospinning techniques to fabricate MgCl₂ catalyzed ammonia borane (AB) nanofibers with a tunable fiber diameter is reported. The synergistic effect obtained by combining nanofibers and metallic catalyst plays a crucial role in the decomposition of MgCl₂-doped AB nanofibers, which leads to significant improvements in dehydrogenation kinetics and complete suppression of unwanted byproducts. The results of dehydrogenation show that MgCl₂-doped AB nanofibers were able to release over 10.0 wt % pure H₂ below 100 °C with favorable kinetics, a significant advance over releases from bulk AB. Furthermore, the dehydrogenation of MgCl₂-doped AB nanofibers gives a weak exothermic reaction, −3.84 kJ mol⁻¹ H₂, which is dramatically lower than that of neat AB (−21 kJ mol⁻¹ H₂), which suggests that the electrospun sample is potentially more feasible to reverse. The findings in this paper provide general guidelines and inspiration for the design and synthesis of novel nano-fibrous materials with controllable dimensions for hydrogen storage applications.