Basic Properties of ZnO, Ga<sub>2</sub>O<sub>3</sub>, and MgO—Quantitative IR Studies
In our previous study, we elaborated a method of determination of concentrations of the basic sites O<sup>2−</sup> and OH<sup>−</sup> in a quantitative IR study of CO<sub>2</sub> adsorption. Previous adsorption studies or TPD experiments only provided the total ba...
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MDPI AG
2024-01-01
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| author | Jerzy Podobiński Jerzy Datka |
| author_facet | Jerzy Podobiński Jerzy Datka |
| author_sort | Jerzy Podobiński |
| collection | DOAJ |
| description | In our previous study, we elaborated a method of determination of concentrations of the basic sites O<sup>2−</sup> and OH<sup>−</sup> in a quantitative IR study of CO<sub>2</sub> adsorption. Previous adsorption studies or TPD experiments only provided the total basicity without distinguishing between O<sup>2−</sup> and OH<sup>−</sup>. In this study, we determined the concentration of O<sup>2−</sup> and OH<sup>−</sup> on ZnO, Ga<sub>2</sub>O<sub>3</sub>, and MgO surfaces. The basicity of ZnO and MgO was found to be significantly higher than that of Ga<sub>2</sub>O<sub>3</sub>. The surface of ZnO was rich in O<sup>2−</sup>, the contribution of OH<sup>−</sup> was very small, and the Ga<sub>2</sub>O<sub>3</sub> surface contained mainly OH<sup>−</sup>. For MgO, the contribution of O<sup>2−</sup> and OH<sup>−</sup> was comparable. According to the IR results, only a small fraction of all surface hydroxyls were sufficiently basic to react with CO<sub>2</sub>. The partial dehydroxylation changed the proportion of the concentrations of O<sup>2−</sup> and OH<sup>−</sup> on the oxides. We also elaborated upon a new method to determine the total concentration of basic sites via CO<sub>2</sub> desorption monitored using IR. For all the oxides, we studied the sum of the concentrations of O<sup>2−</sup> and OH<sup>−</sup>, as determined in our quantitative IR studies, to find whether they were comparable with the total basicity determined in the desorption experiments. |
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| spelling | doaj.art-3667cca779ca44beba5de8484f5c4ce52024-02-23T15:11:27ZengMDPI AGCatalysts2073-43442024-01-0114210610.3390/catal14020106Basic Properties of ZnO, Ga<sub>2</sub>O<sub>3</sub>, and MgO—Quantitative IR StudiesJerzy Podobiński0Jerzy Datka1Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Niezapominajek 8, 30-239 Krakow, PolandJerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Niezapominajek 8, 30-239 Krakow, PolandIn our previous study, we elaborated a method of determination of concentrations of the basic sites O<sup>2−</sup> and OH<sup>−</sup> in a quantitative IR study of CO<sub>2</sub> adsorption. Previous adsorption studies or TPD experiments only provided the total basicity without distinguishing between O<sup>2−</sup> and OH<sup>−</sup>. In this study, we determined the concentration of O<sup>2−</sup> and OH<sup>−</sup> on ZnO, Ga<sub>2</sub>O<sub>3</sub>, and MgO surfaces. The basicity of ZnO and MgO was found to be significantly higher than that of Ga<sub>2</sub>O<sub>3</sub>. The surface of ZnO was rich in O<sup>2−</sup>, the contribution of OH<sup>−</sup> was very small, and the Ga<sub>2</sub>O<sub>3</sub> surface contained mainly OH<sup>−</sup>. For MgO, the contribution of O<sup>2−</sup> and OH<sup>−</sup> was comparable. According to the IR results, only a small fraction of all surface hydroxyls were sufficiently basic to react with CO<sub>2</sub>. The partial dehydroxylation changed the proportion of the concentrations of O<sup>2−</sup> and OH<sup>−</sup> on the oxides. We also elaborated upon a new method to determine the total concentration of basic sites via CO<sub>2</sub> desorption monitored using IR. For all the oxides, we studied the sum of the concentrations of O<sup>2−</sup> and OH<sup>−</sup>, as determined in our quantitative IR studies, to find whether they were comparable with the total basicity determined in the desorption experiments.https://www.mdpi.com/2073-4344/14/2/106basicityCO<sub>2</sub> adsorptionIR spectroscopy |
| spellingShingle | Jerzy Podobiński Jerzy Datka Basic Properties of ZnO, Ga<sub>2</sub>O<sub>3</sub>, and MgO—Quantitative IR Studies Catalysts basicity CO<sub>2</sub> adsorption IR spectroscopy |
| title | Basic Properties of ZnO, Ga<sub>2</sub>O<sub>3</sub>, and MgO—Quantitative IR Studies |
| title_full | Basic Properties of ZnO, Ga<sub>2</sub>O<sub>3</sub>, and MgO—Quantitative IR Studies |
| title_fullStr | Basic Properties of ZnO, Ga<sub>2</sub>O<sub>3</sub>, and MgO—Quantitative IR Studies |
| title_full_unstemmed | Basic Properties of ZnO, Ga<sub>2</sub>O<sub>3</sub>, and MgO—Quantitative IR Studies |
| title_short | Basic Properties of ZnO, Ga<sub>2</sub>O<sub>3</sub>, and MgO—Quantitative IR Studies |
| title_sort | basic properties of zno ga sub 2 sub o sub 3 sub and mgo quantitative ir studies |
| topic | basicity CO<sub>2</sub> adsorption IR spectroscopy |
| url | https://www.mdpi.com/2073-4344/14/2/106 |
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