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机构地区:[1]北京化工大学工业化学研究所,北京100029
出 处:《精细化工》2005年第8期592-596,637,共6页Fine Chemicals
摘 要:研究了发泡镍负载非晶态N iP催化剂的化学沉积法制备过程,考察了影响沉积层中w(P)及负载速率的因素。通过其XRD及SEM表征,得到了催化剂结构与沉积层中w(P)的关系。结果表明:只有w(P)>7%的沉积层才有非晶态的结构特征。比较了普通化学沉积法和脉冲化学沉积法制备的催化剂的活性,发现后者制备的催化剂具有更好的催化性能。通过DSC分析,研究了两种方法制得的催化剂的热稳定性,测定了不同加热速率下的相转移特征温度(Ts,Ton,Tp和Tf),计算得到了两种方法制备的催化剂开始发生相转化的相变激活能Es,结果分别为147.5和149.7 kJ/mol,表明以脉冲化学沉积法制得的催化剂比用普通化学沉积法制得的催化剂具有更好的热稳定性。To study the preparation process of foamed nickel supported amorphous Ni - P alloy catalyst, factors that affect the rate of chemical deposition on the surface of the support and the percentage composition of phosphorus in the deposit layers were investigated. Preferable preparation conditions and chemical composition of the deposition solution were obtained. By X-ray diffraction and SEM, the results show that the deposit layer is in amorphous state only when ω(P) 〉 7%. Properties of the catalysts made by impulse chemical deposition and by ordinary chemical deposition were compared. The characteristic temperatures ( Tg, Ton, Tp and Tf) of phase transfer of the catalysts were measured and the stability of the catalysts was discussed by DSC plots at different heating rates. The phase transfer activation energies (Es) of both catalysts were determined, i. e., 147.5 and 149. 7 kJ/mol respectively. The results show that the activity and the stability of the catalyst obtained by impulse chemical deposition is better than that by ordinary chemical deposition.
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