Solid-state synthesis of amorphous TiB₂ nanoparticles on聽graphene nanosheets with enhanced catalytic dehydrogenation of MgH₂

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• 作者：Guang Liu ; Yijing Wang ; Lifang Jiao ; Huatang Yuan
• 关键词：Hydrogen storage ; Magnesium hydride ; Bi-component catalyst ; Synergistic effect
• 刊名：International Journal of Hydrogen Energy
• 出版年：6 March, 2014
• 年：2014
• 卷：39
• 期：8
• 页码：3822-3829
• 全文大小：2096 K

文摘

A bi-component catalyst TiB₂/GNSs (GNSs is the abbreviation of graphene nanosheets) is synthesized by a solid-state method. Microstructural characterizations based on SEM (scanning electron microscopy), TEM (transmission electron microscopy) and N₂ physisorption show that the size of TiB₂/GNSs catalyst is at nanoscale (20-30聽nm) with a surface area of 84.69聽m²聽g^鈭?. The TiB₂/GNSs nanoparticles ball milled with MgH₂ and exhibit enhanced catalytic effects on the dehydrogenation properties of MgH₂ compares to TiB₂ and GNSs individually. DSC (differential scanning calorimetry) measurements confirm that the peak desorption temperature of MgH₂-5聽wt%TiB₂/GNSs composites can be lowered more than 44聽掳C than the pure as-milled MgH₂. And the dehydrogenation kinetics of TiB₂/GNSs-doped MgH₂ is severalfold acceleration compares to the pure as-milled MgH₂. It is proposed that the TiB₂/GNSs nanoparticles could significantly enhance the intimate interface between TiB₂/GNSs and hydride, therefore, provide more active 鈥渃atalytic sites鈥?and H 鈥渄iffusion channels鈥?to reduce the dehydrogenation temperature and improve the dehydrogenation kinetics of MgH₂. The synergistic effect of nano-GNSs and TiB₂ nanoparticles contributes to the highly efficient for dehydrogenation of MgH₂-5wt%TiB₂/GNSs composites.