副产物对硼氢化钠水解反应的影响

Effect of byproduct on catalytic hydrolysis of sodium borohydride

为了研究副产物对硼氢化钠催化水解反应速率、放氢量及催化剂性能的影响,采用了浸渍法制备717阴离子交换树脂载钌催化剂;采用体积法收集硼氢化钠催化水解生成的氢气;采用SEM观察反应前后的催化剂形貌;采用XRD实验分析反应副产物成分;采用TG-DSC实验分析反应所得的副产物组成.实验结果表明,当不清洗催化剂时,副产物易覆盖在催化剂表面,使反应无法进行;当清洗催化剂时,反应循环的次数增加,但催化剂表面破损严重,致使活性组分流失.若使含10%NaOH的硼氢化钠溶液完全反应,一次加水量应为化学计量比的5倍,放氢量为理论值的87.5%.硼氢化钠催化水解反应副产物是NaBO2.2H2O和NaBO2.4H2O的混合物.

In order to study the effect of byproduct on the catalytic hydrolysis rate of sodium borohydride as well as the volumn of hydrogen generation and performance of catalyst, the ruthenium catalyst loaded on 717 anion exchange resin was prepared by the impregnation method, hydrogen generated by catalytic hydrolysis of sodium borohydride was collected by volume method. The morphology of catalyst before and after the reaction was observed by SEM. The composition of byproduct was analyzed by XRD. The constituent of byproduct was determined by TG-DSC. The experimental results show that the byproduct covers easily on the surface of catalyst without cleaning catalyst, and the reaction can not advance. With cleaning catalyst, the times of reaction cycle get increased. However, the surface of catalyst is seriously damaged, and the active components is washed away. Five times stoichiometric ratio of water needs to be plused in order that the solution of sodium borohydride containing 10% NaOH can completly react where the volumn of hydrogen generation is 87.5% of theoretical value. The byproduct in catalytic hydrolysis of sodium borohydride is the mixture of NaBO2· 2H2O and NaBO2 · 4H2O.