Catalytic Performance of CoB/C for Hydrolysis of NaBH4 Aqueous Solution

The activated carbon supported CoB catalysts were prepared by using impregnation-reduction method (denoted as CoB/C-Imp) and electroless deposition method (denoted as CoB/C-ED), respectively. The catalytic properties were studied on the hydrolysis of NaBH4 aqueous solution. The catalytic activity of CoB/C-ED, CoB/C-Imp and unsupported CoB was 2 022, 2 503 and 1 351 mL.min(-1).g(-1) (Co), respectively. After 5 cycles, the CoB/C-ED could retain 70% initial activity, but CoB/C-Imp and unsupported CoB could only retain 30% and 10% initial activity. The CoB/C-ED shows the best catalytic performance. Furthermore, no obvious decrease in the activity is observed for CoB/C-ED even after it is exposed to air for 30 days, this good anti-oxidation property is favorable for storage and use. Further physicochemical characterization of these catalysts reveals that the unsupported CoB is easily agglomerated and the size of the secondary particles is in the range of 400 similar to 800 nm. After CoB supported on carbon, the agglomeration is greatly restrained. The dispersion of CoB for the CoB/C catalysts is improved compared to the unsupported CoB. The support could also reduce the agglomeration of CoB particles during the catalytic reaction. The CoB particles combine much stronger with the activated carbon. support for the CoB/C-ED catalyst, thus resulting in better dispersion and stability, and lesser leaching.