Tsiotsias Anastasios I, Georgiadis Amvrosios G, Charisiou Nikolaos D, Hussien Aseel G S, Dabbawala Aasif A, Polychronopoulou Kyriaki, Goula Maria A
Laboratory of Alternative Fuels and Environmental Catalysis (LAFEC), Department of Chemical Engineering, University of Western Macedonia, Kozani GR-50100, Greece.
Center for Catalysis and Separations, Khalifa University of Science and Technology, P.O. Box 127788, Abu Dhabi, United Arab Emirates.
ACS Omega. 2024 Feb 28;9(10):11305-11320. doi: 10.1021/acsomega.3c07204. eCollection 2024 Mar 12.
CO adsorbents comprising various alkaline sorption active phases supported on mesoporous AlO were prepared. The materials were tested regarding their CO adsorption behavior in the mid-temperature range, i.e., around 300 °C, as well as characterized via XRD, N physisorption, CO-TPD and TEM. It was found that the NaO sorption active phase supported on AlO (originated following NaNO impregnation) led to the highest CO adsorption capacity due to the presence of CO-philic interfacial Al-O-Na sites, and the optimum active phase load was shown to be 12 wt % (0.22 Na/Al molar ratio). Additional adsorbents were prepared by dispersing NaO over different metal oxide supports (ZrO, TiO, CeO and SiO), showing an inferior performance than that of NaO/AlO. The kinetics and thermodynamics of CO adsorption were also investigated at various temperatures, showing that CO adsorption over the best-performing NaO/AlO material is exothermic and follows the Avrami model, while tests under varying CO partial pressures revealed that the Langmuir isotherm best fits the adsorption data. Lastly, NaO/AlO was tested under multiple CO adsorption-desorption cycles at 300 and 500 °C, respectively. The material was found to maintain its CO adsorption capacity with no detrimental effects on its nanostructure, porosity and surface basic sites, thereby rendering it suitable as a reversible CO chemisorbent or as a support for the preparation of dual-function materials.
制备了负载在介孔AlO上的包含各种碱性吸附活性相的CO吸附剂。对这些材料在中温范围（即约300°C）的CO吸附行为进行了测试，并通过XRD、N物理吸附、CO-TPD和TEM进行了表征。结果发现，负载在AlO上的NaO吸附活性相（通过NaNO浸渍产生）由于存在亲CO的界面Al-O-Na位点而导致最高的CO吸附容量，并且最佳活性相负载量显示为12 wt%（0.22 Na/Al摩尔比）。通过将NaO分散在不同的金属氧化物载体（ZrO、TiO、CeO和SiO）上制备了额外的吸附剂，其性能比NaO/AlO的性能差。还在不同温度下研究了CO吸附的动力学和热力学，结果表明，在性能最佳的NaO/AlO材料上的CO吸附是放热的，并且遵循Avrami模型，而在不同CO分压下的测试表明，Langmuir等温线最适合吸附数据。最后，分别在300°C和500°C下对NaO/AlO进行了多次CO吸附-解吸循环测试。发现该材料保持其CO吸附容量，对其纳米结构、孔隙率和表面碱性位点没有不利影响，从而使其适合作为可逆的CO化学吸附剂或作为制备双功能材料的载体。
