Single Pt Coordinated with Framework Fe in MWW-Type Ferrisilicate toward Efficient Propane Dehydrogenation
Longkang Zhang, Xinyu Chen, Yue Ma, Shaojia Song, Hao Xu, Yejun Guan, Weiyu Song, Jiangwei Zhang, Peng Wu
Abstract
Single atom catalysts have been widely studied due to their high metal dispersity and remarkable catalytic performance. However, stabilizing single-atom metals remains challenging because of the high surface free energy. In this work, framework Fe atom-stabilized single atom Pt were successfully confined into MWW zeolite (Pt@Fe-MWW) by a one-pot synthesis strategy. The isolated skeleton Fe served as anchoring site and promoter to stabilize the single atom Pt via Pt–O–Fe coordination as identified by the in situ CO-IR spectra and XAFS analysis, enabling Pt@Fe-MWW with satisfied activity for the PDH reaction with trace Pt content (<0.01 wt %). A linear relationship between the quantities of Pt–O–Fe coordinated species and the propylene formation rate further confirmed the synergistic catalysis of Pt and skeleton Fe species. A recorded propylene formation rate of Pt (FR C3H6/Pt ) of 1100 mol/g Pt /h was achieved with a Pt content of 0.006 wt %. DFT calculations revealed that the formation of Pt–O–Fe species reduced the dissociation energy of the C–H bonds and facilitated the desorption of H 2, enabling efficient propane dehydrogenation.