低温高效甲醇水液相重整产氢催化剂的开发与研究  

Low-temperature hydrogen production from water and methanol using Pt/α-MoC catalysts

作　　者：林丽利 葛玉振 周武 温晓东[3,4] 石川 马丁[1] Ge Yuzhen;Zhou Wu;Wen Xiaodong;Shi Chuan;Ma Ding(College of Chemistry and Molecular Engineering,Peking University,Beijing 100871;School of Physical Sciences,CAS Key Laboratory of Vacuum Physics,University of Chinese Academy of Sciences,Beijing 100049;State Key Laboratory of Coal Conversion,Institute of Coal Chemistry,Chinese Academy of Sciences,Taiyuan 030001;Syn fuels China Co.Ltd,Beijing 100195;Faculty of Chemical,Environment and Biological Science and Technology,Dalian University of Technology,Dalian 116024)

机构地区：[1]北京大学化学与分子工程学院,北京100871 [2]中国科学院大学物理科学学院中科院真空物理重点实验室,北京100049 [3]中国科学院山西煤炭化学研究所煤转化国家重点实验室,太原030001 [4]中科合成油,北京100195 [5]大连理工大学化工与环境生命学部,大连116024

出　　处：《中国科学基金》2018年第4期376-381,共6页Bulletin of National Natural Science Foundation of China

摘　　要：氢气化学性质活泼,如何实现氢气的高效储存和输运是限制整个氢能源体系发展的瓶颈。一种有效解决上述难题的方法是将氢气存储于高的氢质量含量液体燃料如甲醇中,在需要时通过水和甲醇的液相重整反应,原位释放氢气。而这一过程能够实现的关键在于高效甲醇水重整催化剂的开发。针对这一挑战,本研究团队有目的性地设计合成了一种铂-碳化钼(Pt/α-MoC)双功能催化剂,在190℃时,催化产氢速率高达18 046molH2/(molPt*h),活性较传统铂基催化剂提升了两个数量级。通过对催化剂的结构和催化反应机理详细的研究表明,载体α-MoC与Pt之间存在着强的相互作用,在较低担载量时Pt在α-MoC表面呈原子级分布状态,使贵金属Pt的原子利用率达到最高。Pt/α-MoC表面甲醇水液相重整是一个双中心反应。其中,甲醇和水的氧氢键解离发生在α-MoC载体上,原子级分散的Pt催化甲醇的碳氢键解离;甲醇解离产物CO在Pt-Mo界面处与高表面覆盖度的羟基发生高效水汽迁移反应生成CO2。该研究成果为氢气的低温制备、高效存储运输提供了全新的思路。Hydrogen,an energy-intensive and clean power source,has been treated as an ideal energy carrier to replace the coal and oil based global energy system for the more sustainable economic development.However,the bottle-neck for the bursting of hydrogen economy lies in the efficient and safe hydrogen storage and transportation.To overcome this,methanol can be used as a material for the storage of hydrogen,as it is a liquid at room temperature.With the reforming of methanol and water,hydrogen with a high gravimetric density of 18.8 percent by weight can be in situ released.However,traditional reforming of methanol steam operates at relatively high temperatures and low efficiency.Here we report that platinum（Pt）dispersed onα-molybdenum carbide（α-MoC）enables low-temperature hydrogen production through aqueous-phase reforming of methanol,with an average turnover frequency reaching 18 046 moles of hydrogen per mole of platinum per hour at 190℃.Based on the X-ray absorption fine structure（XAFS）and single atom resolution electron microscopy characterization results,Pt was determined to be atomic dispersed overα-MoC support at the low metal loadings,which maximized the exposure of Pt atom.Based on reaction mechanism investigation and DFT calculation,Pt/α-MoC was proved to be a bifunctional catalyst,withα-MoC support dissociating the O-H bond of H2O and methanol at low temperature,atomic dispersion of Pt scissoring C-H bond of CH3OH.The effectively reforming of intermediates with surface hydroxyls generate CO2 at the interface of Pt/α-MoC.The excellent performance of our catalytic system provide a new strategy for the efficient low-temperature hydrogen production and storage.

关 键 词：单原子铂-碳化钼 低温甲醇水重整 原位产氢 氢气制备与存储 

分 类 号：O643.36[理学—物理化学] TQ116.2[理学—化学]