High coke-resistance MgAl2O4 islands decorated catalyst with minimizing sintering in carbon dioxide reforming of methane
High coke-resistance MgAl2O4 islands decorated catalyst with minimizing sintering in carbon dioxide reforming of methane
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DOI：
10.1016/j.nanoen.2015.11.007
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发表时间：
2016
期刊：
影响因子：
17.6
通讯作者：
In-Hyuk Son;Soonchul Kwon;J. Park;Seung-Jae Lee
中科院分区：
文献类型：
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作者：
In-Hyuk Son;Soonchul Kwon;J. Park;Seung-Jae Lee
甲烷的二氧化碳重整作为一种能源生产过程备受关注，以产生氢气等能源，更重要的是，产生一氧化碳，即所谓的合成气。由于催化剂上的碳沉积和颗粒烧结限制了其在 CH4 的 CO2 重整中的实际应用。对MgO促进的NiCo/Al2O3(NiCoMg/Al2O3)进行蒸汽预处理，在催化剂表面设计MgAl2O4岛，提高催化性能。在蒸汽预处理过程中，不稳定的铝浸出，迁移到MgO上，在催化剂上形成MgAl2O4。密度泛函理论计算和数据分析表明，MgAl2O4与CO2之间的诱导结合能导致CO2容易分解，从而产生NiCo氧化层。这些层显着氧化任何沉积的碳，并抑制碳扩散到镍钴基体中进行晶须类型的碳生长，从而减少催化剂上的碳沉积。在恶劣条件下（GHSV=80,000 h−1 at 850 °C），流处理的 NiCoMg/Al2O3 产生了高转化效率和 3000 小时的高长期稳定性，没有任何明显的碳沉积。值得注意的是，蒸汽预处理导致 NiCoMg/Al2O3 催化剂上形成稳定的 MgAl2O4 岛，从而防止碳沉积。
Carbon dioxide reforming of methane has attracted much attention as an energy production process to generate energy sources such as hydrogen and more importantly, carbon monoxide, so called syn-gas. Because carbon deposition and sintering of particles on a catalyst limit its practical application for CO2reforming of CH4. Steam pre-treatment was performed on MgO promoted NiCo/Al2O3(NiCoMg/Al2O3) to design MgAl2O4islands over the catalyst surface, improving catalytic performance. During steam pre-treatment, unstable aluminum leached out, migrating to the MgO so as to form MgAl2O4on the catalyst. Density functional theory calculations and data analysis show that the induced binding energy between MgAl2O4and CO2leads to the facile decomposition of CO2thus producing oxidized layers of NiCo. These layers significantly oxidize any deposited carbon and inhibit carbon diffusion into NiCo matrix for the whisker type of carbon growth, reducing carbon deposition on the catalyst. Under severe conditions (GHSV=80,000 h−1at 850 °C), the stream treated NiCoMg/Al2O3yielded a high conversion efficiency and high long-term stability for 3000 h without any notable carbon deposition. It is worthwhile to noting that the steam pre-treatment led to stable MgAl2O4islands on the NiCoMg/Al2O3catalyst preventing carbon deposition.