Study On The Preparation Of Highly Efficient Dehydrogenation Catalysts And Their Catalytic Performance

Exploring catalysts with high-efficiency for dehydrogenation has attracted much attention in the field of new energy.Methylcyclohexane（MCH）and ammonia borane（AB）have been considered as superior hydrogen storage materials.In this work,highly efficient MCH and AB dehydrogenation catalysts were synthesized by using two different methods.On one hand,in situ synthesis of nanometer sized noble-metal catalysts during the heating of reactor of MCH dehydrogenation can effectively avoid fast surface oxidation of catalysts before catalytic reactions.On the other hand,the technique of laser ablation in liquids sometimes introduces grain boundaries into the nano catalysts due to quenching effect,which may promote the catalytic activity in AB dehydrogenation.Firstly,Pt/C catalysts with nanoparticle diameter of 1.8 nm,clean suface,and uniform distribution have been in situ synthesized through thermal decomposition of Pt（acac）₂ during the heating of reactor.The analysis of hydrogen evolution illustrates that the conversion of MCH over Pt loading of 0.68wt% is nearly 97% at 320 ℃,with a maximum hydrogen generation rate of 580 mmol/gpt/min.Secondly,nano-Ru colloidal solution was obtained by laser ablation in liquid and mixed with the supports,i.e.,Al₂O₃ and mesoporous carbon.The Ru nanocrystals contain numbers of grain boundaries and the diameter of these nanocrystals is about 9.8 nm.The turnover frequency is 276.7 mol H2 min-1 mol-1Ru.The activation energy for the hydrolysis of AB in the presence of Ru/Al₂O₃ catalysts was measured to be 30.9 kJ/mol.Finally,we propose several in situ loading methods for supported catalysts by laser ablation in liquid,including laser ablating metals and metal salts.Ni/Si O₂ and Pt-based catalysts were synthesized and the technical parameters were optimized.