【摘要】：隨著現代社會的發(fā)展,對能源的需求增長迅猛,而目前以化石燃料為主的能源消耗帶來了嚴重的環(huán)境污染,因此尋找可再生的綠色能源成為當前全球亟待解決的任務。氫氣由于能量密度高、來源廣、燃燒產物無污染等特點被公認為是未來最清潔的能源之一。氫氣作為一種能量載體而不是一種能源已經被廣泛應用于內燃機、質子交換膜燃料電池和其他各種燃料電池中。本文采用化學鍍法在鐵片上鍍覆了一層Ni-Co-P非晶合金鍍層,采用單因子變量的試驗方法系統(tǒng)研究了還原劑次亞磷酸鈉濃度、主鹽硫酸鎳和硫酸鈷濃度及其比例、緩沖劑氟化銨濃度、絡合劑檸檬酸鈉濃度和鍍液pH、溫度等對鍍層沉積速率的影響,最后根據實驗要求得出優(yōu)化的鍍液配方和工藝參數。采用優(yōu)化配方和工藝參數在γ-Al2O3小球和納米碳纖維上鍍覆Ni-Co-P合金催化劑,采用能量色散X射線譜儀(EDS)、電感耦合等離子體原子發(fā)射光譜儀(ICP-AES)、場發(fā)射掃描電子顯微鏡(SEM)、X射線衍射(XRD)、化學吸附儀(BET)等手段對樣品的元素組成、形貌和結構等進行了綜合表征,用硼氫化鈉水解制氫反應考察了Ni-Co-P合金催化劑的催化性能。結果表明,N1-Co-P/γ-Al2O3非晶合金催化劑具有非常粗糙的表面和很大的表面積,對催化硼氫化鈉溶液水解具有良好的催化活性和循環(huán)使用性能,通過對動力學數據研究分析得出高鎳Ni-Co-P/γ-Al2O3非晶合金催化劑的活化能Ea=36.76 kJ·mol-1,高鈷Ni-Co-P/γ-Al2O3非晶合金催化劑的活化能為Ea=52.05 kJ·mol-1;而對Ni-Co-P/CNFs合金催化劑的研究表明,該催化劑的組成為Ni1.58Co9.71P1,其在45℃,催化劑濃度為7.5 g.L-1,氫氧化鈉濃度為5 wt%,硼氫化鈉濃度為2.5 wt%時,氫氣釋放速率達到最大值18.044 L·g-1·min-1,通過對負載型催化劑Ni-Co-P/CNFs催化堿性硼氫化鈉溶液釋放氫氣動力學數據研究得出該催化劑的活化能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 緯-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/ 緯-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/ 緯-Al2O3 amorphous alloy catalyst Ea=36.76 kJ mol-1, high cobalt Ni-Co-P/ 緯-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，

本文編號：2401715