太阳能甲烷重整中催化活性吸收体的表面特性

以AISI316泡沫金属为基体为太阳能甲烷重整反应制备出系列Ru基和Ni基催化活性吸收体(Ru/Al2O3/AISI316,Ni/Al2O3(MgO)/AISI316),着重利用XRD、TPR、TPD和CO2脉冲吸脱附等技术对所制整体式催化剂的表面特性进行了表征和分析.结果表明:以AISI316泡沫金属为基体可增加活性组分与涂层载体Al2O3的相互作用以及活性物种的分散度.对于Ni基催化活性吸收体,在涂层载体中添加MgO助剂可显著地提高Ni/Al2O3/AISI316的催化活性;Al2O3涂层载体含量的增加可提高活性组分NiO的分散性.相对Ni/Al2O3/AISI316,Ru/Al2O3/AISI316催化活性吸收体对CO2的吸附和活化能力更强,因而具有相对更高的催化活性.

Surface Properties of the Catalytically Active Absorber for Solar Reforming of Methane

Solar CO2 reforming of methane has attracted a great attention because it can realize energy storage of high-temperature heat from concentrated solar radiation and optimal utilization of resources of natural gas. Catalytically active absorber has a key role on absorption of solar energy and reforming of methane and becomes focus of solar reforming of methane research. Catalytically active absorber, Ru/Al2O3/AISI316, Ni/Al2O3(MgO)/AISI316, were firstly fabricated by using AISI316 metal foam as the matrix. The surface properties of the resulting catalytically active absorber were characterized by means of XRD, H2-TPR and CO2-TPD techniques. Combination of the reactivity behavior of the as-prepared samples in a continuous flow fixed-bed reaction system with a quartz tube reactor, it can be found that the high activity and the long-term stability of Ru/Al2O3/AISI316 foam was unaffected by the components changes of in AISI316 foam matrix during the high temperature reaction. For nickel based catalytically active absorber, the activity for methane reforming of CO2 can be improved by adding the promoter MgO or increasing the Al2O3 coating. Based on the characterization of XRD and H2-TPR, AISI316 foam matrix can enhance the interaction between the Al2O3 coating and the active species Ru or Ni, particularly for Ru/Al2O3/AISI316, the formed Ru-O-Al surface species can lead to the increase of high dispersion of active species. From the peak area of adsorption and desorption behavior, the activating and absorption ability of CO2 on Ru/Al2O3/AISI316 is higher than that of Ni/Al2O3/AISI316, which ascribes to the more active sites on the surface of the catalytically active absorber.