Abstract Carbon dioxide (CO2) emissions are of global concern because of climate change. CO2 methanation is one of the most prestigious technologies to convert CO2 into value-added products such as substitute natural gas. In this study, a highly active fibrous silica-mordenite (FS@SiO2-MOR) catalyst has been synthesized by a microemulsion process and characterized by XRD, TEM, FESEM, N2 adsorption analysis, FTIR-pyrrole, CO2-TPD, and ESR spectroscopy. The CO2 methanation reaction was performed, and it was found that the FS@SiO2-MOR catalyst exhibited higher CH4 selectivity (68%) and CO2 conversion (65%) due to the distinctive fibrous morphology, which provided higher surface area, basic sites, and oxygen vacancies. In addition, the synthesized FS@SiO2-MOR catalyst exhibited high thermal stability (50 hours) and significantly suppressed coke deposition compared to commercial mordenite. According to in-situ FTIR observations, the carbonyls and linear CO2* were the essential intermediates species for the formation of methane during CO2 methanation via an associative mechanism.

中文翻译：

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用于增强 CO2 甲烷化的高活性纤维状二氧化硅-丝光沸石 (FS@SiO2-MOR) 鸡冠形催化剂的制备和表征

摘要 由于气候变化，二氧化碳 (CO2) 排放受到全球关注。二氧化碳甲烷化是将二氧化碳转化为替代天然气等增值产品的最负盛名的技术之一。本研究采用微乳液法合成了一种高活性纤维状二氧化硅-丝光沸石 (FS@SiO2-MOR) 催化剂，并通过 XRD、TEM、FESEM、N2 吸附分析、FTIR-吡咯、CO2-TPD 和 ESR 光谱表征. 进行了 CO2 甲烷化反应，发现 FS@SiO2-MOR 催化剂表现出更高的 CH4 选择性（68%）和 CO2 转化率（65%），这是由于独特的纤维形态，提供了更高的表面积、碱性位点、和氧空位。此外，与商业丝光沸石相比，合成的 FS@SiO2-MOR 催化剂表现出高热稳定性（50 小时）并显着抑制焦炭沉积。根据原位 FTIR 观察，羰基化合物和线性 CO2* 是通过缔合机制在 CO2 甲烷化过程中形成甲烷的必要中间体。