Propane Dehydrogenation over PtSn/Al2O3 Catalysts: Influence of Urea to Al(NO3)3·9H2O Ratio

Xiaohan Wang,Zean Xie,Xia Xiao,Zhen Zhao,Jing Cui,Jiaxin Song,Ning Zhang,Xiaoqiang Fan,Lian Kong

doi:10.3390/catal12020157

Abstract

Al2O3 supports were synthesized by the hydrothermal method and PtSn/Al2O3 catalysts were prepared by incipient-wetness impregnation method. The influence of the ratio of urea to Al(NO3)3·9H2O on the structure and catalytic performance for propane dehydrogenation was investigated. The catalysts were characterized by XRD, N2 adsorption–desorption, SEM, H2-TPR, NH3-TPD and Raman. The results show that the ratios of urea to Al(NO3)3·9H2O influence the morphology and phy-chemical properties of Al2O3 support, which influence the dispersion of PtSn active sites and the interaction of Pt and Sn on PtSn/Al2O3 catalysts. The PtSn/Al2O3-9 catalyst possesses the highest interaction of Pt and Sn, which result in high dispersion of active sites. The PtSn/Al2O3-9 catalyst shows high propane conversion and low deactivation rate among these catalysts.

Highlights

Propene as an important platform chemical is widely used in organic and polymer synthesis
The dispersion and nature of the PtSn active sites are affected by the Al2O3 support, which influences the catalytic performance for propane dehydrogenation (PDH) reaction
In order to investigate the morphology of the Al2O3 support, Scanning electron microscopy (SEM) characterization was IcnarorridederotuotiannvdestthigeaitmeatgheesmaroerpshhoowlongyinoFf itghuerAe l12.OIt3 csaunpbpeorste,eSnEtMhacththareaPcttSerni/zAatl2iOon3w2aesxchairbriitesdiorruetgaunldarthmeoirmpahgoelsogayrewshitohwsnoimn eFisghuereet-1l.ikItecsatnrubcetusereesn. tThhatethsiezePtoSfn/shAele2tO-l3i-k2e esxtrhuibcittusrierriengcurleaarsemsowrpihtholtohgeyiwncitrheassoemien suhreeeat-ltiokeAslt(rNucOtu3)r3e·9sH

Summary

Introduction

Propene as an important platform chemical is widely used in organic and polymer synthesis. Sn as an efficient promoter can enhance the dissociative adsorption of propane and weaken the adsorption of propene [5,6,7,8,9] Promoters such as In, Ga, Zn, Cu, Mn and Ir are effective in enhancing catalytic performance by the geometric effect or/and electronic effect [10,11,12,13,14,15,16,17]. Al2O3 support has been proven to affect the physical and chemical properties [33], which may influence the dispersion of metal active sites so as to affect the catalytic performance h[3a4s]b. The dispersion and nature of the PtSn active sites are affected by the Al2O3 support, which influences the catalytic performance for PDH reaction

Results

Coke Analysis

Catalyst Characterization

Catalytic Activity Measurements

Conclusions