Pt–Co spatially separated catalyst for efficient and stable propane dehydrogenation reaction

Abstract

Propane dehydrogenation (PDH) is a promising method to satisfy the growing demand for propylene. Still, the traditional Pt-based catalysts are susceptible to sintering and coking, which leads to the deactivation of the catalysts; thus, developing stable and efficient catalysts for PDH is of significant importance to the industry. Herein, we prepared an efficient and stable PDH catalyst (Co/Pt@A) by encapsulating Pt particles in A zeolite and then loading Co species onto its surface. A co-impregnated PtCo/A catalyst was also prepared for comparison. The results show that the agglomeration and growth of Pt and Co particles of Co/Pt@A catalyst are effectively prevented during high-temperature reactions. Furthermore, the hydrogen spillover effect of the Co/Pt@A catalyst is significantly enhanced. The H species on Pt particles migrates through the A zeolite to the surface Co particles, enabling the coke precursors on the support to be quickly saturated and eliminated, reducing coke formation. In contrast, the Pt–Co closely contacted structure of the PtCo/A catalyst leads to the sintering of PtCo particles and a limited hydrogen spillover on the support surface. The catalytic performance in propane dehydrogenation shows that after 6 h, the C₃H₈ conversion and C₃H₆ selectivity of the Co/Pt@A catalyst are higher than those of the PtCo/A catalyst. This bimetallic spatially separated structure provides a new insight for the design and preparation of efficient catalysts for the PDH and many other reactions.