The Synthesis And The Reaction Of CO Oxidation Over The Supported Fe-Pt/Al₂O₃Catalyst

CO as a pollutant gas, it is important to eliminate it at low temperature in many areas.In the last three decades, noble metals have got more and more attention because of itseffective property for low temperature CO oxidation. Early people focus on studying goldcatalysts. However, some shortcomings of the gold catalysts, such as instability at hightemperature pretreatments, limited its application. Conversely, the supported platinumcatalyst has good stability and water resistant, these qualities make it become a hot topic.In our previous work, we prepared the Pt colloids by the method of without using theprotective agent, and then loaded on the Fe2O3. The Pt/Fe2O3catalyst has high reactivity inCO oxidation at low temperature, and always has good stability under wet conditions, thecatalyst is not deactivated after3000h in continuous reaction. In addition, we had studiedthe influence of various factors in the formation of Pt colloidal and the influence of variousparameters was systematically investigated on the Pt NPs particle size. We have a morein-depth understanding in the reaction mechanism of CO on Pt/Fe2O3catalysts. With thisbackground, we prepared Fe-Pt/MOxcatalysts which Fe was introduced as an additive inthis paper. Since the Pt/Fe2O3catalyst has many inconveniences to characterize iron, whichcontain iron oxide carrier and the Fe that has strong interaction with Pt NPs. We selectAl2O3which is considered as an inert carrier to support the Pt NPs and iron oxide. Througha series of characterization, we have a better understanding of the structure and redoxproperty of the Fe-Pt/Al2O3catalyst, as well as the reaction mechanism based on the Pt-Fecatalysts for CO oxidation. The main results of this paper are showed as follows:1. The influence of various parameters on preparing Fe-Pt/MOxcatalystsThe Fe-Pt/MOx catalysts were prepared by colloid deposition. We selected Al2O3tosupported Pt NPs and iron oxide. Various parameters for preparing Fe-Pt/Al2O3catalyst were studied. And their performances in CO oxidation were also studied. We found that thecontents of Pt and the Pt/Fe ratios had a great impact in the activity of the catalysts.2. The reaction mechanism of CO oxidation over Fe-Pt/Al2O3catalyst.We Prepared a series nFe-1Pt/Al2O3(n=0.1,0.5,1,3) catalysts by the method thatmentioned above. For comparison, FeOx/Al2O3and Pt/Al2O3catalyst were also preparedby the same method. Furthermore, we prepared3Fe-1Pt/Al2O3catalyst in different pH.Using in-situ DRIFT, X-ray photoelectron spectroscopy, H2-TPR and anothercharacterization, we found that when the atomic ratio of Pt and Fe was1/3, the interactionbetween Pt and Fe, may form a Pt-O-Fe structure. Respectively, CO activate on Pt, oxygenspecies were provided by the Pt-O-Fe structure. After the reaction, oxygen molecules addedto the O vacancies, O active on the Pt-O-Fe structure. It may have such Fe3+Fe2+redox cycle, which has played a very important role in the reaction of CO oxidation.