Preparation and Catalytic Performances of Pt-M (M=Sn, Ir and Co) Nanoalloy Catalysts for Propane Dehydrogenation
|School||East China University of Science and Technology|
|Keywords||Propane dehydrogenation Catalyst Pt-Sn bulk alloy Chemical reduction mehtod|
Supported Pt-Sn bimetallic catalyst is one of the widely used catalysts in propane dehydrogenation process. Although it has been industrialized for many years, this catalyst still suffers from coking and deactivation. Many research work has been focused on the structure-performance relationship and improving catalytic performance. Unsupported,γ-Al2O3 and carbon nanotube supported PtSn bulk alloy (intermetallic compound) with different compositions and structural properties and Pt-X (X=Ir, Co) nanoalloy were prepared by chemical reduction method using NaBH4 as reduction agents. All the catalysts were characterized by XRD, N2 physisorption, HRTEM, H2 chemisorption and TPO-TPR methods and tested in propane dehydrogenation. It was found that PtSn, PtSn2, Pt2Sn3 and PtSn4 bulk alloys could be synthesized by the method used in this article. The obtained alloys had single crystallinity and the Pt/Sn ratios in these alloys were similar to those in the precursor solutions. The activity ofγ-Al2O3 supported alloy catalyst increased with the decrease of Pt/Sn ratio. Supported PtSn4 catalyst had the highest activity. Though its initial activity is lower than that of single Pt catalyst, the alloy catalyst had higher stability and activity after 3 hours reacting than that of Pt catalyst. Carbon nanotube supported PtSn alloy catalyst has higher performances thanγ-Al2O3 supported catalysts. Core-shell structure was not observed in Pt-Co and Pt-Ir alloy prepared in this article and their catalytic perfromances is inferior to PtSn alloys. The results obtained here were helpful for illustration of the effect of occurrence of PtSn alloys in Pt-Sn bimetallic catalysts on the catalyst deactivation and maybe useful for the development of highly efficient propane dehydrogenation catalyst.