Preparation Of Ruthenium-based Catalyst And Its Catalytic Performance Toward Ammonia-borane Hydrolysis

Hydrogen（H₂）is recognized as a clean energy carrier at present due to its non-toxicity,environmental friendliness and high energy density,which is a most promising alternative to fossil fuels to solve the problems of traditional energy pollution and scarcity.It is also an excellent choice to complete the policy of"carbon neutralization and carbon peak"during the14th Five-Year Plan period.However,there are still many problems in the current traditional methods for hydrogen production,such as high energy consumption,inconvenient storage and transportation,making it difficult for hydrogen to be used on a large scale in daily life.Therefore,it is very important to develop a new hydrogen preparation method.Ammonia borane（NH₃BH₃,AB）is an ideal solid material for hydrogen storage,with hydrogen content of as high as 19.6 wt%.In the presence of appropriate catalysts,it can realize rapid hydrolysis to release hydrogen without any impurity gas.Due to high catalytic activity,the supported noble metals are the most common catalysts,but precious metal resources are scarce and very expensive.Therefore,reducing the amount of noble metals in catalyst while ensuring its catalytic performance is an important research direction toward ammonia borane hydrolysis for hydrogen production.In this work,metal organic frameworks（MOFs）were used as precursors to produce catalyst carriers by carbonization and phosphating and ruthenium（Ru）was anchored on these carriers through the reduction by AB or hydrogen gas.Therefore,Ru₁/Co PCP-1000 and Ru₂Cu@C-350 and Ru/（Co Ni）P@PC-500 catalysts with excellent performance were achieved by optimizing the reaction temperatures,different carriers and Ru contents.Taking the hydrolysis of ammonia borane to produce hydrogen as model reaction,it is found that due to the strong interaction between Ru and metal phosphide substrate,Ru/（Co Ni）P@PC-500catalyst exhibits the best performance with turnover frequency（TOF）of 572.6mol _H2·mol _Ru^-1·min^-1.In addition,benefitting from the special hollow structure of Co PCP and the synergistic effect between Co and Ru,Ru₁/Co PCP-1000 catalyst show a very low activation energy（E_a）of 31.25 k J·mol^-1.Moreover,Ru₁/Co PCP-1000 also demonstrates superior cycle stability with a catalytic activity of 72.8%after 10 consecutive tests.The catalyst prepared in this dissertation provides more possibilities for ammonia borane hydrolysis from the perspective of green energy,cost control and practicability.