Highly dispersed Ni/Al2O3 catalysts for dry reforming of methane prepared by alkaline-induced adsorption process
Highly dispersed Ni/Al2O3 catalysts for dry reforming of methane prepared by alkaline-induced adsorption process
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DOI：
10.1016/j.ijhydene.2022.01.217
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发表时间：
2022-08-22
影响因子：
7.2
通讯作者：
Luo, Yongming
中科院分区：
文献类型：
--
作者：
Liu, Xupeng;Zhang, Lei;Luo, Yongming
Ni-Al催化剂在甲烷干法重整等有价值的反应中得到了广泛的应用，但Al_2O_3载体上Ni物种的低利用率限制了其进一步的应用。在碱性条件下，镍物种被诱导锚定在介孔氧化铝上。值得注意的是，碱处理导致了介孔Al_2O_3的腐蚀和重组，这种Al_2O_3的重组过程和配体不饱和Al~(3+)缺陷的存在促进了Ni物种在表面上的均匀分散。结合TEM、HRTEM、UV-Vis和H-2化学吸附分析，发现在碱性条件下，Al_2O_3形成了一种特殊的层状堆积结构，有利于Ni物种在催化剂表面的均匀分布。令人惊讶的是，该催化剂具有良好的低温DRM反应活性，优于传统的浸渍法制备的Ni-Al催化剂和文献报道的大多数Ni-Al催化剂。在550℃时，RCH4-MNI的甲烷重整速率为80.16(L/小时/克)。而吸附Ni-Al催化剂的甲烷重整反应速率RCH_4-MnI R-CH_4MNi=160.87(L/h/g)。因此，本工作为合成高效的用于DRM的Ni-Al催化剂以及其他有意义的反应提供了一些思路。(C)2022年氢能出版物有限责任公司。爱思唯尔有限公司出版。保留所有权利。
Ni-Al catalysts were widely developed for methane dry reforming (DRM) and other valuable reactions, but the low utilization of Ni species on the Al2O3 support has limited its further application. In this paper, Ni species were induced to anchor on the mesoporous Al2O3 under alkaline conditions. Notably, alkaline treatment caused the corrosion and restructure of the mesoporous Al2O3, and this reorganization process of Al2O3 and the presence of defects from ligand-unsaturated Al3+ (Al-penta(3+)) promoted Ni species to remain uniform dispersion on the surface. In combination with TEM, HRTEM, UV-vis and H-2 chemisorption, it is observed that Al2O3 formed a special layered stacking structure under alkaline conditions, which contributed to the homogeneous distribution of Ni species on the catalyst surface. Surprisingly, the catalyst showed good low-temperature DRM reactivity, which was superior to the conventional Ni-Al catalysts prepared by impregnation method and the most Ni-Al catalysts reported in the literatures. The CH4 reforming rate of RCH4-mNi = 80.16 (L/h/g) at 550 ? was obtained on the conventional impregnation catalyst, while the Ni-Al catalysts by adsorption showed a significant increase in the CH4 reforming rate of RCH4-mNi R-CH4_mNi = 160.87 (L/h/g). Consequently, the present work provides some ideas for the synthesis of efficient Ni-Al catalysts for DRM as well as other meaningful reactions. (c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.