负载型催化剂Ni-Co-P的制备及释氢性能研究

发布时间：2019-01-05 11:18

【摘要】：随着现代社会的发展,对能源的需求增长迅猛,而目前以化石燃料为主的能源消耗带来了严重的环境污染,因此寻找可再生的绿色能源成为当前全球亟待解决的任务。氢气由于能量密度高、来源广、燃烧产物无污染等特点被公认为是未来最清洁的能源之一。氢气作为一种能量载体而不是一种能源已经被广泛应用于内燃机、质子交换膜燃料电池和其他各种燃料电池中。本文采用化学镀法在铁片上镀覆了一层Ni-Co-P非晶合金镀层,采用单因子变量的试验方法系统研究了还原剂次亚磷酸钠浓度、主盐硫酸镍和硫酸钴浓度及其比例、缓冲剂氟化铵浓度、络合剂柠檬酸钠浓度和镀液pH、温度等对镀层沉积速率的影响,最后根据实验要求得出优化的镀液配方和工艺参数。采用优化配方和工艺参数在γ-Al2O3小球和纳米碳纤维上镀覆Ni-Co-P合金催化剂,采用能量色散X射线谱仪(EDS)、电感耦合等离子体原子发射光谱仪(ICP-AES)、场发射扫描电子显微镜(SEM)、X射线衍射(XRD)、化学吸附仪(BET)等手段对样品的元素组成、形貌和结构等进行了综合表征,用硼氢化钠水解制氢反应考察了Ni-Co-P合金催化剂的催化性能。结果表明,N1-Co-P/γ-Al2O3非晶合金催化剂具有非常粗糙的表面和很大的表面积,对催化硼氢化钠溶液水解具有良好的催化活性和循环使用性能,通过对动力学数据研究分析得出高镍Ni-Co-P/γ-Al2O3非晶合金催化剂的活化能Ea=36.76 kJ·mol-1,高钴Ni-Co-P/γ-Al2O3非晶合金催化剂的活化能为Ea=52.05 kJ·mol-1;而对Ni-Co-P/CNFs合金催化剂的研究表明,该催化剂的组成为Ni1.58Co9.71P1,其在45℃,催化剂浓度为7.5 g.L-1,氢氧化钠浓度为5 wt%,硼氢化钠浓度为2.5 wt%时,氢气释放速率达到最大值18.044 L·g-1·min-1,通过对负载型催化剂Ni-Co-P/CNFs催化碱性硼氢化钠溶液释放氢气动力学数据研究得出该催化剂的活化能Ea=51.57 kJ·mol-1。
[Abstract]:With the development of modern society, the demand for energy is increasing rapidly, and the energy consumption based on fossil fuels has brought serious environmental pollution. Therefore, the search for renewable green energy has become an urgent task in the world. Hydrogen is regarded as one of the cleanest energy sources in the future due to its high energy density, wide sources and no pollution. Hydrogen, as an energy carrier rather than an energy source, has been widely used in internal combustion engines, proton exchange membrane fuel cells and other fuel cells. In this paper, a layer of Ni-Co-P amorphous alloy coating was deposited on iron sheet by electroless plating. The concentration of sodium hypophosphite, the concentration of nickel sulfate and cobalt sulfate of main salt and its proportion were systematically studied by single factor variable test method. The effects of ammonium fluoride concentration of buffer agent sodium citrate concentration of complex agent and pH, temperature of plating solution on the deposition rate of the coating were discussed. Finally the optimized solution formulation and process parameters were obtained according to the experimental requirements. Ni-Co-P alloy catalysts were coated on 纬-Al2O3 pellets and carbon nanofibers with optimized formulation and process parameters, and (EDS), inductively coupled plasma atomic emission spectrometer (ICP-AES) was used. The elemental composition, morphology and structure of the samples were characterized by field emission scanning electron microscope (SEM), X), (SEM), X ray diffraction (XRD),) chemisorbent apparatus (BET) and so on. The catalytic performance of Ni-Co-P alloy catalyst was investigated by hydrolysis of sodium borohydride to produce hydrogen. The results show that the N1-Co-P/ 纬-Al2O3 amorphous alloy catalyst has a very rough surface and a large surface area, and has good catalytic activity and recycling performance for the hydrolysis of sodium borohydride solution. The activation energy of high nickel Ni-Co-P/ 纬-Al2O3 amorphous alloy catalyst Ea=36.76 kJ mol-1, high cobalt Ni-Co-P/ 纬-Al2O3 amorphous alloy catalyst is obtained by analyzing the kinetic data. The activation energy of the amorphous alloy catalyst is Ea=52.05 kJ mol-1;. The study of Ni-Co-P/CNFs alloy catalyst shows that the composition of the catalyst is Ni1.58Co9.71P1, the catalyst concentration is 7.5 g 路L ~ (-1) and the concentration of sodium hydroxide is 5 wt%, at 45 鈩，

本文编号：2401715