Chiang Nan-Chian, Ju Tz-Jie, Wang Yi-Cheng, Lin Tzu-Peng, Guo Jia-Han, Lin Shawn D
Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 10617, Taiwan.
ACS Appl Mater Interfaces. 2025 May 14;17(19):28163-28172. doi: 10.1021/acsami.4c17644. Epub 2025 May 1.
CO capture and utilization are a must for easing the global warming caused by the use of fossil fuels. Previous studies demonstrate the possibility of thermal deoxygenation of CO to CO over the vacancies of CeO. This study examines the influence of the dopant to CeO on the deoxygenation of CO to CO, wherein the examined dopants include Zr, Gd, Sm, and In. Only In-doped CeO exhibits significant reactivity for CO deoxygenation in our sequential temperature-programmed reduction (TPR) and CO-TPRx (temperature-programmed reaction) tests up to 700 °C. InCeO after H-TPR demonstrates a deoxygenation onset temperature as low as 400 °C and it can maintain a stable performance in cycle tests. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses indicate that In exsolutes from the fluorite framework during TPR and the exsoluted In become oxidized in the subsequent CO deoxygenation reaction. XPS indicates that the redox of Ce also occurs during TPR-CO-TPRx with InCeO. InO by itself demonstrates a higher deoxygenation onset temperature, a lower per gram deoxygenation capacity, and a poorer stability than InCeO under the same test conditions, while CeO is inactive. The results suggest a synergy between exsoluted In and the fluorite substrate, leading to the observed deoxygenation activity of In-doped CeO.
捕获和利用一氧化碳对于缓解因使用化石燃料而导致的全球变暖至关重要。先前的研究表明，在CeO的空位上，一氧化碳热脱氧生成二氧化碳具有可能性。本研究考察了CeO掺杂剂对一氧化碳脱氧生成二氧化碳的影响，其中考察的掺杂剂包括Zr、Gd、Sm和In。在我们高达700℃的程序升温还原（TPR）和CO-TPRx（程序升温反应）测试中，只有In掺杂的CeO对一氧化碳脱氧表现出显著的反应活性。H-TPR后的InCeO显示出低至400℃的脱氧起始温度，并且在循环测试中能够保持稳定的性能。X射线衍射（XRD）和X射线光电子能谱（XPS）分析表明，In在TPR过程中从萤石骨架中析出，并且析出的In在随后的一氧化碳脱氧反应中被氧化。XPS表明，在InCeO的TPR-CO-TPRx过程中Ce也发生了氧化还原反应。在相同测试条件下，In2O3本身显示出更高的脱氧起始温度、更低的每克脱氧容量以及比InCeO更差的稳定性，而CeO则无活性。结果表明析出的In与萤石基底之间存在协同作用，导致观察到In掺杂CeO的脱氧活性。
