关键词: 活性炭, 催化剂载体, 活化条件, Co-B/C催化剂, 硼氢化钠, 制氢

Abstract:

Cotton stalk-based activated carbons were prepared by phosphoric acid activation of cotton stalks (CS) in a fluidized bed. The Co-B catalysts supported on cotton stalk-based activated carbon were generated by the impregnation-chemical reduction method. Meanwhile, the prepared activated carbons and catalysts were characterized by nitrogen physisorption, FTIR, XRD and SEM. The effects of activation reaction parameters, reaction temperature and recycle times on hydrogen generating performance of the activated carbons supported Co-B catalysts were investigated. The optimal activation temperature, activation time and amount of activator (m_H3PO4/m_CS) for activation of cotton stalk were 500℃, 1 h and 0.75, respectively. Under these conditions, the as-prepared Co-B/C catalyst with 14.5% (mass) Co exhibited the best hydrogen generating performance with an average rate of hydrogen generation up to 12.06 L·min^-1·(g Co)^-1 at 25℃. Activation energy of hydrogen generation reaction on such catalyst was estimated to be 44.61 kJ·mol^-1. After five cycles, the catalyst retained 54% initial activity, exhibiting high activity and stability.

Key words: activated carbon, catalyst support, activation condition, Co-B/C catalyst, sodium borohydride, hydrogen production