Methanolysis of sodium borohydride in the presence of supported catalysts

In this study, catalysts were synthesized by using the impregnation method for the catalytic methanolysis of NaBH4. TiO2, Al2O3 and AC were used as support materials in the produced catalysts. Salts of 3d transition metals such as NiCl2.6H2O, CoCl2.6H2O, CuCl2.2H2O, FeCl3, MnCl2.2H2O and RuCl3.2H2Owere used in the formation of active centers. The active metals used in the preparation of the catalysts were in binary and triple mixtures. NaBH4 was decomposed by methanolysis by means of synthesizedcatalysts and the hydrogen gas was released. The volume of hydrogen gas produced in the experiments carried out at 25 ºC was recorded using the reverse burette method. The highest hydrogen production rate among the trials was 5667 mL H2/gkat.min. This value was obtained by using 34(Ni0,7Co0,3/TiO2) catalyst. In the two- and three-metal catalyst trials, it was generally found that Ni presence enhance theactivity. In addition, it has been determined that the catalytic performance can be improved in binary form. XRD, SEM and TEM analyzes of selected catalysts were performed before and after methanolysis. EDAX results showed that active metals remained on the surface after methanolysis. By TEM analysis, it was determined that active metals showed homogeneous distribution on the support surface. Size analysis of these particles was made using various software and the average particle size was measured around 7 nm. The reusability of the catalyst has been tested and found that it retains its activity even after ten uses. In order to obtain kinetic data on 97(Ni0,85Co0,1Fe0,05/TiO2)catalyst, methanolysis processes were carried out at 10, 25 and 30 ºC temperatures. Using these data, the activation energy of the catalyst was found to be 46,02 kJ mol-1. Tests also reveal that the reaction obeys zero rate order.