| At present, energy and environmental issues are the focus of attention of national, natural resources are a large number of consumption, environment pollution is serious, so the development of clean new energy become the research focus. DMFC has been widely studied as one of the many clean energy.It has a low operating temperature, low noise, clean environment and high energy density, is ideal mobile power and fixed small power station.At present, Pt catalysts is considered to be the best catalyst in DMFC, but it is precious metal, and easy to poisoning by CO intermediates, the stability of the catalyst is bad, and its storage quantity is little, the price is expensive, prevent the commercialization of DMFC. Therefore, the research and develop a highly active, low cost and the high stability anode electric catalyst becomes the key to DMFC commercialization.Amorphous alloy atomic arrangement long-range disorder, very conducive to adsorption reaction molecular, is considered to be a kind of materials with high stability, high catalytic activity. The system study of Ni-B amorphous nano materials catalytic oxidation performance of methanol is relatively lacking. For this reason, this article will use the chemical reduction method to prepareddifferent Ni/B ratio of amorphous nanoparticles. system to investigate the Ni-B amorphous alloy electric catalytic oxidation properties of methanol. The results of the study are as follows:Physics characterization result show that Ni-B alloy samples is amorphous structure, the shape is spherical, the average particle size about 20 nm, there are mild reunion. DSC results show that with the increase of B content in the alloy,the initial crystallization temperature first rise after falling, Ni1B4 catalyst have the highest crystallization temperature, thermal stability is the best. XPS analysis showed that with the increase of B, the oxygen content is first rising after falling,Ni1B3 amorphous catalyst have the best oxidation resistance. Relative to the simple substance B, B1 s electron binding energy increases, shows that B lost part of electrons, the electron binding energy of Ni element is reduced, surplus electronics. in Ni-B amorphous alloy the main composition is Ni2 B. In addition,the surface of B/Ni ratio in the alloy less than the input of B/Ni ratio, with the increase of B, the surface of B/Ni ratio increase on the whole.Electrochemical testing results show Ni-B amorphous nano alloy has significant effect to methanol electrooxidation, different catalyst in 1.0 M Na OH+ x M CH3 OH electrolyte, the highest catalytic activity is in 1.0 M NaOH + 1.0M CH3 OH solution, with the increase of the B content, the Ni-B amorphous nano alloy catalytic activity decrease after rising first, Ni1B4 oxidation peak current is the highest, the catalytic performance is best. Ni-B catalyst reaction order are not identical, there are little differences. Tafel slope is little difference,but Tafel intercept is rise after decrease first. With the increase of methanol concentration, the reaction resistance is rise after decrease, at 1.0 M NaOH + 1.0M CH3 OH solution, Ni1B4 have the minimum resistance value, is 22.63 ?.Chronoamperometric curves indicates that at the beginning, current reduced quickly, after a period of time remained stable, showing a certain ability to resist CO poisoning, Ni1B4 has the best ability to resist CO poisoning. On Ni-B amorphous nano alloy electrode, diffusion-kinetics control speed is the methanol oxidation reaction control steps. The reaction activation energy is 15.42 KJ. |
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