Efficient catalytic properties of SO42−/M O (M = Cu, Co, Fe) catalysts for hydrogen generation by methanolysis of sodium borohydride

The SO42−/MxOy (M = Cu, Co, Fe) catalysts were prepared and applied to hydrogen production from methanolysis of sodium borohydride for the first time. The morphologies and properties of the as-prepared catalysts were characterized by XRD, BET, FT-IR, TEM and SEM-EDX techniques. Under our experimental conditions, SO42−/CuO exhibits much higher catalytic activity than those of SO42−/CoO and SO42−/Fe2O3 catalysts and follows the order of SO42−/CuO > SO42−/CoO > SO42−/Fe2O3, which is opposite to order of BET surface area, implying that the methanolysis of sodium borohydride is not a structure-sensitive reaction. It can be inferred that both acidic and metallic sites are responsible for the high catalytic performance of the SO42−/MxOy catalysts towards NaBH4 methanolysis. In addition, the effects of the concentrations of NaBH4 and methanol, catalyst dosage, and reaction temperature on the hydrogen generation rate have been investigated using SO42−/CuO as catalyst. The SO42−/CuO-catalyzed methanolysis reaction follows a power law, i.e. r = A·exp (−13135/RT)·[NaBH4]1.01·[CH3OH]1.60·[Catalyst]0.52. The apparent activation energy was calculated to be 13.13 kJ/mol.