Xin Zhang1,2, Zhuanghe Ren1, Yunhao Lu1, Jianhua Yao2, Mingxia Gao1, Yongfeng Liu1,3, Hongge Pan1. 1. State Key Laboratory of Silicon Materials, Key Laboratory of Advanced Materials and Applications for Batteries of Zhejiang Province and School of Materials Science and Engineering , Zhejiang University , Hangzhou 310027 , China. 2. Institute of Laser Advanced Manufacturing, Collaborative Innovation Center of High-End Laser Manufacturing Equipment , Zhejiang University of Technology , Hangzhou 310014 , China. 3. Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education) , Nankai University , Tianjin 300071 , China.
Abstract
Herein, we synthesize successfully ultrafine TiN nanoparticles (<3 nm in size) embedded in N-doped carbon nanorods (nano-TiN@N-C) by a facile one-step calcination process. The prepared nano-TiN@N-C exhibits superior catalytic activity for hydrogen storage in NaAlH4. Adding 7 wt % nano-TiN@N-C induces more than 100 °C reduction in the onset dehydrogenation temperature of NaAlH4. Approximately 4.9 wt % H2 is rapidly released from the 7 wt % nano-TiN@N-C-containing NaAlH4 at 140 °C within 60 min, and the dehydrogenation product is completely hydrogenated at 100 °C within 15 min under 100 bar of hydrogen, exhibiting significantly improved desorption/absorption kinetics. No capacity loss is observed for the nano-TiN@N-C-containing sample within 25 de-/hydrogenation cycles because nano-TiN functions as an active catalyst instead of a precursor. A severe structural distortion with extended bond lengths and reduced bond strengths for Al-H bonding when the [AlH4]- group adsorbs on the TiN cluster is demonstrated for the first time by density functional theory calculations, which well-explains the reduced de-/hydrogenation temperatures of the nano-TiN@N-C-containing NaAlH4. These findings provide new insights into designing and synthesizing high-performance catalysts for hydrogen storage in complex hydrides.
Herein, we synthesize successfully ultrafine TiN nanoparticles (<3 nm in size) embedded in N-doped n class="Chemical">carbon nanorods (nano-TiN@N-C) by a facile one-step calcination process. The prepared nano-TiN@N-C exhibits superior catalytic activity for hydrogen storage in NaAlH4. Adding 7 wt % nano-TiN@N-C induces more than 100 °C reduction in the onset dehydrogenation temperature of NaAlH4. Approximately 4.9 wt % H2 is rapidly released from the 7 wt % nano-TiN@N-C-containing NaAlH4 at 140 °C within 60 min, and the dehydrogenation product is completely hydrogenated at 100 °C within 15 min under 100 bar of hydrogen, exhibiting significantly improved desorption/absorption kinetics. No capacity loss is observed for the nano-TiN@N-C-containing sample within 25 de-/hydrogenation cycles because nano-TiN functions as an active catalyst instead of a precursor. A severe structural distortion with extended bond lengths and reduced bond strengths for Al-H bonding when the [AlH4]- group adsorbs on the TiN cluster is demonstrated for the first time by density functional theory calculations, which well-explains the reduced de-/hydrogenation temperatures of the nano-TiN@N-C-containing NaAlH4. These findings provide new insights into designing and synthesizing high-performance catalysts for hydrogen storage in complex hydrides.