LiAlH4 supported on TiO2/hierarchically porous carbon nanocomposites with enhanced hydrogen storage properties
LiAlH4 supported on TiO2/hierarchically porous carbon nanocomposites with enhanced hydrogen storage properties
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DOI：
10.1039/c6qi00200e
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发表时间：
2016-11
影响因子：
7
通讯作者：
Yaran Zhao;Mo Han;Haixia Wang;Chengcheng Chen;Jun Chen
中科院分区：
文献类型：
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作者：
Yaran Zhao;Mo Han;Haixia Wang;Chengcheng Chen;Jun Chen
采用一步溶剂法制备了TiO 2/分级多孔碳（LAH-TiO 2/HPC）负载LiAlH 4纳米复合材料，并研究了其催化脱氢性能。制备的TiO 2/HPC纳米复合材料表明，TiO 2纳米颗粒（~ 10 nm）均匀分布在分级多孔碳（HPC）表面。结果表明，纳米TiO 2/HPC复合材料对LiAlH 4的脱氢反应和脱氢后样品的再氢化反应具有较好的催化性能。含37wt%LiAlH_4、25wt%TiO_2和38wt%HPC的37 LAH-25 TiO_2/38 HPC的脱氢温度最低。氢在64 °C开始释放，这比纯LiAlH 4低约100 °C。此外，在130 °C下40 min内，37 LAH-25 TiO 2/38 HPC可释放4.3 wt%的氢，表明具有快速动力学，活化能为47.1 ± 3.5 kJ mol−1。此外，它可以在300 °C和4 MPa的氢气压力下重新吸附H2。LiAlH 4在具有高比表面积的多级多孔碳中的纳米约束和具有Ti（4+）/Ti（3+）/Ti（2+）缺陷位的TiO 2纳米颗粒的高分布在LiAlH 4的储氢性能中发挥协同作用。
We report the synthesis of LiAlH4 supported on TiO2/hierarchically porous carbon (LAH–TiO2/HPC) nanocomposites using a one-step solvent method and their enhanced catalytic dehydrogenation performance. The as-prepared TiO2/HPC nanocomposites show that TiO2 nanoparticles (∼10 nm) are homogeneously distributed on the surface of hierarchically porous carbon (HPC). The results show that TiO2/HPC nanocomposites exhibit better catalytic performance for the dehydrogenation of LiAlH4 and rehydrogenation of the dehydrided sample than that of TiO2 nanoparticles and HPC. The dehydrogenation temperature of 37LAH–25TiO2/38HPC with 37 wt% LiAlH4, 25 wt% TiO2 and 38 wt% HPC is the lowest. Hydrogen started to be released at 64 °C, which is about 100 °C lower than that of pure LiAlH4. In addition, 4.3 wt% of hydrogen could be released from 37LAH–25TiO2/38HPC within 40 min at 130 °C, indicating fast kinetics with an activation energy of 47.1 ± 3.5 kJ mol−1. Furthermore, it can re-adsorb H2 at 300 °C under a hydrogen pressure of 4 MPa. The nanoconfinement of LiAlH4 into hierarchically porous carbon with high surface areas and the high distribution of TiO2 nanoparticles with a Ti(4+)/Ti(3+)/Ti(2+) defect site play a synergistic role in improving the hydrogen storage properties of LiAlH4.