文献类型：期刊文献

英文题名：Composition-Tuned Ni-Ce Mixed Oxides with Inverse CeO2/Ni Structure for Enhanced Low-Temperature CO2 Methanation

作者：Fang, Yuan[1];Liu, Jundi[1];Zhang, Chengxi[2];Liu, Kande[1];Ju, Ziying[1];Meng, Xuan[1];Liu, Naiwang[1];Shi, Li[1]

机构：[1]East China Univ Sci & Technol, Int Joint Res Ctr Green Energy Chem Engn, Shanghai 200237, Peoples R China;[2]Sinopec Res Inst Petr Proc Co Ltd, Beijing 100083, Peoples R China

年份：2026

卷号：65

期号：8

起止页码：4311

外文期刊名：INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH

收录：;EI(收录号：20261020206040);WOS:【SCI-EXPANDED(收录号:WOS:001697389600001)】；

基金：The authors acknowledge the support of the State Key Laboratory of Petroleum Molecular & Process Engineering through its Open Research Program.

语种：英文

外文关键词：Carbon dioxide - Catalyst selectivity - Inverse problems - Methanation - Nickel - Nickel oxide - Phase interfaces - Rhenium compounds - Temperature

摘要：This work systematically investigates the effect of Ni/Ce molar ratios (0.3-2.9) on the structure-activity relationship of Ni/Ce mixed oxides for low-temperature CO2 methanation. As the Ni/Ce ratio increased, the rate of CO2 conversion gradually increased. At a GHSV of 12,000 mL & centerdot;g(-1)h(-1), all catalysts exhibited 100% CH4 selectivity. The best-performing NiCe-2.1 catalyst not only achieved 37.2% CO2 conversion at 200 degrees C but also maintained above 85% CO2 conversion during the stability test at 250 degrees C. Characterization (XRD, BET, TEM, H-2-TPR/TPD, CO2-TPD, XPS) results revealed that when Ni/Ce <2.1, the catalyst exhibited a conventional Ni/CeO2 structure. The specific surface area gradually decreased with an increasing Ni content. The activity enhancement of Ni/CeO2 structure primarily resulted from the absolute increase in the number of Ni-O-Ce interface sites. When Ni/Ce = 2.1, the catalyst formed an inverse CeO2/Ni structure, which re-exposed the CeO2 surface and significantly restored the specific surface area. TOF analysis confirmed that the interfacial sites in the inverse structure had higher intrinsic activity, thereby further improving the low-temperature activity. When Ni/Ce >2.1, excessive independent NiO phases caused severe nickel agglomeration, inhibiting the formation of additional Ni-O-Ce interfaces. Finally, in situ DRIFTS results revealed that the CO2 methanation on NiCe-2.1 mainly followed the formate pathway (CO2* -> HCO3* -> HCOO* -> CH4).