Bi-functional hydrotalcite-derived NiO-CaO-Al2O3 catalysts for steam reforming of biomass and/or tar model compound at low steam-to-carbon conditions
Bi-functional hydrotalcite-derived NiO-CaO-Al2O3 catalysts for steam reforming of biomass and/or tar model compound at low steam-to-carbon conditions
复制标题
DOI：
10.1016/j.apcatb.2015.02.017
复制
发表时间：
2015-08-01
影响因子：
22.1
通讯作者：
Kawi, S.
中科院分区：
文献类型：
--
作者：
Ashok, J.;Kathiraser, Y.;Kawi, S.
研究了由类水滑石前驱体衍生的NiO-CaO-Al2O3 （Ni-Ca-Al）催化剂在甲苯蒸汽重整和生物质反应中的双官能团性质。通过改变水蒸气重整反应中Ca/Al摩尔组成比，探讨了NiO-CaO-Al2O3催化剂对CO2吸附性能的影响。在低蒸汽碳比（S/C= 1）条件下，研究了甲苯反应的蒸汽重整。Ni-Ca-Al的最佳催化剂组成（8:62:30）在稳定性和活性方面都具有优异的催化性能。在S/C值为1时，Ni-Ca-Al（8:62:30）催化剂在甲苯重整反应中表现出稳定的24 h甲苯转化率，接近70%。在650℃时，约85%的生物质通过Ni-Ca-Al（8:62:30）转化为气态产物，是所有测试催化剂中最高的。还原催化剂和废催化剂的XRD分析表明，Ni- ca - al（8:62:30）催化剂上活性金属Ni的团聚速率明显低于其他催化剂。TPR和XPS分析表明，Ni-Ca-Al催化剂煅烧后和还原后分别为Ca(Ni, Al)O固溶体形态。CO2 - TPD研究表明，Ni-Ca-Al催化剂的碱度（8:62:30）高于其他Ni-Ca-Al催化剂。在甲苯蒸汽重整反应中，Ni-Ca-A1（8:62:30）催化剂上的积碳速率为2.5 mgcg (-1) h(-1)，也是所有催化剂中最低的。因此，低碳沉积速率是其催化性能相对稳定的原因之一。(C) 2015 Elsevier B.V.版权所有
In this paper, the bi-functional properties of NiO-CaO-Al2O3 (Ni-Ca-Al) catalysts derived from hydrotalcite-like precursors were explored for steam reforming of toluene and biomass reactions. The influence of CO2 sorption property of NiO-CaO-Al2O3 catalysts was also explored by changing Ca/Al molar composition ratio for steam reforming reaction. The steam reforming of toluene reaction was investigated at low steam-to-carbon conditions (S/C= 1). An optimum catalyst composition of Ni-Ca-Al(8:62:30) gave superior catalytic performance in terms of stability and activity in both the reforming reactions. At S/C value of I, Ni-Ca-Al(8:62:30) catalyst displayed a stable toluene conversion of near 70% for a period of 24 h tested in toluene reforming reaction. At 650 degrees C, about 85% of biomass was converted to gaseous products over Ni-Ca-Al(8:62:30), which is the highest among all the catalysts tested. The XRD analysis of reduced and spent catalysts shows that the rate of agglomeration of active metallic Ni species over Ni-Ca-Al(8:62:30) catalyst is considerably lesser when compared to other catalysts. The TPR and XPS analyses reveals that the calcined and reduced Ni-Ca-Al catalysts are in Ca(Ni, Al)O solid solution form, respectively. CO2 - TPD studies shows that the basicity of Ni-Ca-Al(8:62:30) catalyst is higher compared to other Ni-Ca-Al catalysts. The rate of carbon deposition over Ni-Ca-A1(8:62:30) catalyst during steam reforming of toluene reaction is 2.5 mgC g(-1) h(-1), which is also the lowest among all the catalysts. Hence, the low carbon deposition rate is one of the reasons for its stable catalytic performance compared to the rest. (C) 2015 Elsevier B.V. All rights reserved.