Promoting effects of Fe-Ni alloy on co-production of H2 and carbon nanotubes during steam reforming of biomass tar over Ni-Fe/α-Al2O3
Promoting effects of Fe-Ni alloy on co-production of H2 and carbon nanotubes during steam reforming of biomass tar over Ni-Fe/α-Al2O3
复制标题
Fe-Ni合金对Ni-Fe/α-Al2O3生物质焦油蒸汽重整联产H2和碳纳米管的促进作用
DOI：
10.1016/j.fuel.2020.118116
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发表时间：
2020-09-15
期刊：
影响因子：
7.4
通讯作者：
Xiang, Jun
中科院分区：
文献类型：
--
作者：
He, Limo;Hu, Song;Xiang, Jun
制备了 Fe/Ni 摩尔比为 0、0.5、1 和 2 的 Fe 改性 Ni/Al2O3 催化剂，以促进作为焦油模型化合物的甲苯蒸汽重整过程中 H-2 和碳纳米管（CNT）的联产。添加Fe后，甲苯转化率从Ni/Al2O3的55.1%提高到F1N1A的73.6%（Fe/Ni比为1），并且F1N1A的H-2收率达到最大值，超过2000 mmol/(g-cata)。生成平均直径为 10-30 nm 的多壁碳纳米管，并遵循尖端生长机制。与Ni/Al2O3相比，Fe的添加显着提高了碳纳米管的数量和质量，且碳纳米管具有更长的长度和更少的弯曲度。添加Fe后对H-2和CNT的双重促进作用归因于Fe-Ni合金中Ni和Fe之间的强相互作用。 Fe-Ni合金对甲苯和H2O的分解性能具有较高的活性，可以生成更多的H-2和中间体，从而改善重整反应。同时，高催化分解活性提供了更多的碳物种，Fe-Ni合金的形成增强了金属碳化物的生成，促进了碳纳米管的生长。此外，Fe的添加抑制了无定形碳的沉积，减弱了Ni颗粒与催化剂载体之间的相互作用，从而保持了催化剂的活性并促进了CNT的尖端生长。
Fe-modified Ni/Al2O3 catalysts with Fe/Ni molar ratios of 0, 0.5, 1 and 2 were prepared to promote the co-production of H-2 and carbon nanotubes (CNTs) during steam reforming of toluene as a tar model compound. After the addition of Fe, toluene conversion increased from 55.1% of Ni/Al2O3 to 73.6% of F1N1A (Fe/Ni ratio of 1), and H-2 yield over F1N1A reached the maximum of more than 2000 mmol/(g-cata). Multi-walled carbon nanotubes with average diameter of 10-30 nm were generated and follow tip-growth mechanism. Compared with Ni/Al2O3, the addition of Fe remarkably increased the amount and quality of CNTs which had longer length and less tortuosity. These dual promoting effects on H-2 and CNTs after the addition of Fe were attributed to the strong interaction between Ni and Fe in Fe-Ni alloy. Fe-Ni alloy had the high activity for the decomposition performance of toluene and H2O to generate more H-2 and intermediates for improving the reforming reaction. Meanwhile, the high catalytic decomposition activity supplied more carbon species and the formation of Fe-Ni alloy enhanced the generation of metal carbide for promoting CNTs growth. Besides, the deposition of amorphous carbon was suppressed and the interaction between Ni particle and catalyst support was weakened after the addition of Fe, which kept the activity of catalyst and promoted the tip-growth of CNTs.