Hydrogen Generation From Ammonia Decomposition And Separation By Palladium Membrane

Ammonia is an appropriate carrier for hydrogen due to its much higher gravimetric capacity for hydrogen storage (17.6%), ease in liquefaction at a mild condition (i.e. 30℃ and 8 atm), well-established infrastructure for its production and distribution and being environmentally benign. Most recently, catalytic decomposition of ammonia has been an attractive way to produce CO_x-free hydrogen for fuel cell uses. Supported Pd membranes possess many advantages, such as high selectivity and permeability, good resistance to raised temperature and pressure, etc., while compared with other conventional separation technologies for hydrogen. Further enrichment of hydrogen from the product mixture of ammonia decomposition by hydrogen transport membrane (HTM) would be an economical way to provide pure hydrogen for the proton exchange membrane fuel cell (PEMFC). Therefore, the aim of this thesis is to deeply investigate the reaction kinetics of ammonia decomposition, synthesis of novel and high-performance catalyst for this catalytic route, and the application of palladium membrane in the case of hydrogen generation from ammonia.The reaction kinetics of ammonia decomposition over the nickel and ruthenium nanoparticles have been detailed, by which the particle size effect has been proved through the direct correlation between the intrinsic activity and the average particle size of the active phase. It has been observed that the cluster size of metal strongly influenced the turnover rate and the optimal value appeared at around 2 nm. Based on this result, we have succeeded in exploring a novel polyol reduction-homogeneous...