Hydrogen Generation From Catalytic Hydrolysis Of Soddium Borohydride Solution Using Supported Alloy Catalysts

With the development of global industrial economy, the concerns over the environmental pollution and the depletion of fossil fuels supplies and global warming attributable to the greenhouse effect caused by a steep increase in carbon dioxide and other gases have made hydrogen one of the most promising future energy resources. However, the development of effective, reliable and safe hydrogen storage materials is the most important challenge for the first half of this century and beyond. Hydrogen is a well-known energy carrier, not an energy source. It has been suggested as an alternative to traditional fuels since it can be used directly in internal combustion engines or other types of fuel cells.In this paper, Ni-Co-P amorphous alloy catalysts were coated on iron sheets by electroless deposition. The influence of sodium hypophosphite, nickel suffate, cobalt sulfate heptahydrate, ammonium fluoride, trisodium citrate dehydrate concentration and pH value, temperature of the bath on deposition rate, bath stability and coating quality were investigated by single factor method. Then the optimized formula and process conditions was summarized.Based on the result, Ni-Co-P alloy catalysts were synthesized via electroless depositon on aluminum oxide and carbon nanofibers. Energy dispersive X-ray spectrometer (EDS), inductively coupled plasma-atomic emission spectrometer (ICP-AES), field emission scanning electron Microscope (SEM), X-ray diffraction (XRD) and nitrogen adsorption-desorption isotherm were used to characterize surface element composition, morphology and structure of the catalysts. Hydrogen generation from the hydrolysis of sodium borohydride solution was used to evaluate the catalytic activity of the Ni-Co-P/γ-Al2O3 catalysts. The results show that the as-prepared Ni-Co-P alloy catalysts supported on γ-Al2O3 have a very rough surface, which give the catalysts a large specific surface area. The prepared catalysts exhibit high catalytic activity and reusability in hydrogen generation from catalytic hydrolysis of sodium borohydride solution. The reported work also includes the full experimental details for the collection of a wealth of kinetic data to determine the activation energy. The results show that the Ni-Co-P/γ-Al2O3 catalysts with a high nickel content have a activation energy of 36.76 kJ·mol-1 while the Ni-Co-P/γ-Al2O3 catalysts with a high cobalt content have a activation energy of 52.05 kJ·mol-1. Research on Ni-Co-P/CNFs catalysts suggests that the Ni-Co-P/CNFs catalysts have a formula of Ni1.58Co9.71P1. And A maximum hydrogen generation rate of 18.044 L·g-1·min-1 is achieved at 45 ℃ by hydrolysis of 2.5 wt% NaBH4 solution containing 5 wt% NaOH and 7.5 g·L-1 Ni-Co-P/CNFs catalysts with a Ni-Co-P loading of 18.127 wt%. The activation energy of the Ni-Co-P/CNFs catalysts for the hydrolysis of alkaline NaBH4 solution is found to be 51.57 kJ·mol-1.