Industrial & Engineering Chemistry Research, Vol.57, No.13, 4505-4513, 2018
Deactivation Mechanism and Regeneration Study of Ga-Pt Promoted HZSM-5 Catalyst in Ethane Dehydroaromatization
Direct nonoxidative conversion of ethane to aromatics has become an effective way of upgrading shale gas. Metal-promoted shape selective zeolite catalysts are often used for aromatization. Although the coking issue of the catalysts in ethane aromatization has been reported, the deactivation mechanism and the performance of regenerated Ga-Pt promoted HZSM-5 needs to be further investigated. The objective of this study is to elucidate deactivation mechanism of Ga-Pt promoted HZSM-5 and investigate the feasibility of regenerating deactivated catalysts for commercial viability. When using lower concentration of oxygen (2 vol %) for regeneration, decreased catalyst deactivation rate was observed. The metal particle size, crystalline structures, and acidity are characterized by various analytical instrumentations (TEM, XRD, NH3-TPD). The change of Bronsted acidity was observed on regenerated catalysts. The results showed that metal agglomeration and leaching of Pt from homogeneous Ga-Pt particle were the main causes of deactivation other than coke deposition, indicating that stabilization of bimetallic metal particles on zeolite surface is critical.