Evolution of catalyst coated atomised magnesium spheres - An alternative thermal storage medium for concentrated solar power applications
Evolution of catalyst coated atomised magnesium spheres - An alternative thermal storage medium for concentrated solar power applications
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催化剂涂层雾化镁球的演变——聚光太阳能应用的替代蓄热介质
DOI：
10.1016/j.ijhydene.2017.09.095
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发表时间：
2017
影响因子：
7.2
通讯作者：
Mistry P
中科院分区：
文献类型：
--
作者：
Mistry P
对两种商业气体雾化球形镁粉末（平均直径为26μm和30μm）进行了高温循环研究，其表面涂有磁控溅射催化剂（铬、铁、钒和不锈钢）。在350 °C下，催化剂的存在促进更快的反应动力学，同时提高容量，直到第90次循环接近稳定，例如发现V_Mg30的归一化容量从45.5%上升到65.5%。以下确定的活化能（从基辛格图）和微观结构分析的后循环结构的机制，提出了不同的演变的未涂覆和涂覆的Mg粉的基础上，在一个复杂的过程中，颗粒烧结与颗粒破碎竞争。催化剂有效性随温度变化，在400 °C下50次循环后对雾化Mg粉末的储氢特性具有可忽略的影响，这主要与催化剂中缺乏多价性有关。
Elevated temperature cycling studies were performed on two commercial gas atomised Mg spherical powders (average diameter of 26μm and 30μm) with magnetron sputtered catalysts (chromium, iron, vanadium and stainless steel) applied to their surfaces. At 350 °C, the presence of a catalyst promotes faster reaction kinetics with improving capacity until approaching stabilisation by the 90th cycle, e.g. the normalised capacity of V_Mg30 was found to rise from 45.5% to 65.5%. Following determination of activation energies (from Kissinger plots) and microstructural analysis of the post cycled structures a mechanism was proposed for the differing evolutions of the uncoated and coated Mg powders based upon a complex process in which particle sintering competes with particle fragmentation. Catalyst effectiveness varied with temperature, having a negligible impact on hydrogen storage characteristics of the atomised Mg powders following 50 cycles at 400 °C and this was mainly associated with the lack of multivalency in the catalysts.