Ni/CeO2 based catalysts as oxygen vectors for the chemical looping dry reforming of methane for syngas production
Ni/CeO2 based catalysts as oxygen vectors for the chemical looping dry reforming of methane for syngas production
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DOI：
10.1016/j.apcatb.2017.04.048
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发表时间：
2017-09-05
影响因子：
22.1
通讯作者：
Jalowiecki-Duhamel, Louise
中科院分区：
文献类型：
--
作者：
Loefberg, Axel;Guerrero-Caballero, Jesus;Jalowiecki-Duhamel, Louise
甲烷的化学链干重整（CLDRM）通过将Ni/CeO 2固体以循环方式暴露于CH 4和CO2来进行。该固体在暴露于CH 4期间充当氧载体，产生合成气（CO + H2），并在暴露于CO2期间被重新氧化。在合成气生产过程中不存在CO2允许抑制逆水煤气变换反应并达到高选择性。暴露于CO2中可恢复载体的氧容量并去除表面形成的残余碳，从而使催化剂完全再生。采用TPR、XRD、拉曼散射和XPS等方法对固体进行了表征。结果表明，在成环过程中，部分镍被还原并保持在金属状态。另一方面，即使在暴露于甲烷之后，也观察到与Ce阳离子强相互作用的Ni 2+物种。两种Ni物种对反应物活化和固体供氧都起重要作用。Ni负载量是控制载体还原行为的关键参数，因此也是CLDRM工艺优化的关键参数。(C)2017爱思唯尔B. V.保留所有权利。
Chemical looping dry reforming of methane (CLDRM) is performed by exposing a Ni/CeO2 solid to CH4 and CO2 in a cyclic way. The solid acts as an oxygen vector producing syngas (CO + H2) during exposure to CH4, and is re-oxidized during exposure to CO2. Absence of CO2 during syngas production allows suppressing reverse water gas shift reaction and reaching high selectivity. Exposure to CO2 restores the oxygen capacity of the support and removes residual carbon formed at the surface, thus fully regenerating the catalyst. Solids were characterized by TPR, XRD, Raman scattering, and XPS. Results show that part of the Ni is reduced and remain in metallic state during the looping process. On the other hand, Ni2+ species in strong interaction with Ce cations are observed even after exposure to methane. Both Ni species play important roles on reactants activation and oxygen supply by the solid. Ni loading is a crucial parameter for controlling the reduction behavior of the support and therefore for CLDRM process optimization. (C) 2017 Elsevier B.V. All rights reserved.