Ag催化剂对MnO2吸氢催化活性的研究

为降低碱性锌锰电池因Zn负极腐蚀产生H2而引起的较高内压,采用在不同碳载体上沉积Ag的方法分别制备了不同的Ag催化剂,对比研究了Ag单独作为催化剂与含助催化剂Ce或Ni和Bi的Ag催化剂对MnO2吸H2量的影响,并探讨了各种Ag催化剂的催化活性及助催化剂的作用机理.研究表明:Ag/C值高的吸氢催化效果好;助催化剂Ce或Ni和Bi的共同加入,可大幅度地提高以活性炭为载体的Ag催化剂的催化效果,其中载体为活性炭2时,提高幅度超过100%;Ni和Bi的共同加入,使Ag结晶趋向于无定形化,而Ce的加入,减小了Ag结晶的晶粒尺寸,有助于提高其比表面积,这说明无定形化和减小晶粒尺寸均可提高Ag对MnO2吸收H2的催化活性.

Studies of Ag catalyzers used in H2 absorption of MnO2 electrodes

In order to reduce the higher inner pressure of alkaline Zn-MnO_2 battery due to the H_2 arises from the corrosion of Zinc anode, some Ag catalyzers have been made by Depositing Ag on different carbons. The effects of the various catalyzers which consist of Ag or Ag with catalyst-accelerators of elements Ce or Ni and Bi on the amounts of H_2 that the MnO_2 electrodes absorb were tested contrastively and the performance and mechanism of the various Ag catalyzers work on reaction that MnO_2 absorbs H_2 were investigated. From the studies above some conclusion were obtained as follow. The MnO_2 electrode including Ag catalyzer with larger ratio of Ag/C absorbed larger amount of H_2. Added with the catalyst-accelerator of elements Ce or Ni and Bi in the Ag catalyzers, the H_2 absorption of MnO_2 electrodes with Ag catalyzers based on activated carbons was raised sharply and the increment of H_2 absorption of MnO_2 electrode with Ag catalyzer based on activated carbon 2 exceeded 100%. Added with Ni and Bi, Ag crystal deposited on activated carbon tended to amorphism. Added with Ce, the size of Ag crystal deposited on activated carbon was reduced, so the surface area of the Ag crystal would be enlarged. Which indicate that being amorphous and reducing the size of the Ag particles, the performance of Ag catalyzers on reaction that MnO_2 absorbs H_2 can be enhanced.