Catalytic performance of Ni catalysts supported on CeO2 with different morphologies for low-temperature CO2 methanation
Catalytic performance of Ni catalysts supported on CeO2 with different morphologies for low-temperature CO2 methanation
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DOI：
10.1016/j.cattod.2020.08.010
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发表时间：
2021-06-22
期刊：
影响因子：
5.3
通讯作者：
Ratchahat, Sakhon
中科院分区：
文献类型：
--
作者：
Jomjaree, Thapanee;Sintuya, Paweennut;Ratchahat, Sakhon
采用水热/湿法浸渍法制备了一系列不同形貌的CeO 2负载Ni催化剂，包括纳米多面体（PH）、纳米棒（NR）、纳米颗粒（NP）和纳米立方体（NC）。以低温CO2甲烷化为反应条件，考察了催化剂的催化性能。Ni/CeO 2催化剂表现出优于METH（R）134（一种商业甲烷化催化剂）的上级CO2转化率和CH 4选择性。实验发现以下活性顺序：Ni/CeO 2-PH > Ni/CeO 2-NR > Ni/CeO 2-NP > Ni/CeO 2-NC > METH（R）134。在不同CeO 2形貌的催化剂中，Ni/CeO 2-NR催化剂的比表面积最大，还原度最高，具有较高的氧空位/储氧能力（OSC）。然而，由H-2-TPR确定的Ni/CeO 2-NR催化剂的Ni和Ce之间的强金属-载体相互作用（SMSI）对低温下的CO2转化率造成负面影响。出乎意料的是，Ni/CeO 2-PH催化剂具有约100 nm的单晶CeO 2纳米结构。7.4纳米，具有相对高的比表面积和高还原性，特别是在低还原温度下。因此，Ni/CeO 2-PH催化剂是低温CO2甲烷化的最佳催化剂。
In this study, a series of Ni catalysts supported on CeO2 with different morphologies including nanopolyhedrons (PH), nanorods (NR), nanoparticles (NP) and nanocubes (NC) was prepared via hydrothermal / wet impregnation method. The catalytic performance of as-prepared catalysts was evaluated for low-temperature CO2 methanation. The Ni/CeO2 catalysts exhibited a superior CO2 conversion and CH4 selectivity over METH (R) 134, a commercial methanation catalyst. The following order of activity was experimentally found : Ni/CeO2-PH > Ni/CeO2-NR > Ni/CeO2-NP > Ni/CeO2-NC > METH (R) 134. Among different CeO2 morphologies, the Ni/CeO2-NR catalyst exhibited the largest surface area and the highest reducibility, providing the high oxygen vacancies/oxygen storage capacity (OSC). Nevertheless, the strong metal-support interaction (SMSI) between Ni and Ce of the Ni/CeO2-NR catalyst determined by H-2-TPR posed a negative impact on the CO2 conversion at low temperature. Unexpectedly, the Ni/CeO2-PH catalyst possessed a single crystalline CeO2 nanostructure of ca. 7.4 nm with relatively high surface area and high reducibility especially at low reduction temperature. Therefore, the Ni/CeO2-PH catalyst was found to be the optimum catalyst for low-temperature CO2 methanation.