The effect of strong metal–support interaction (SMSI) on Pt–Ti/SiO2 and Pt–Nb/SiO2 catalysts for propane dehydrogenation. Issue 17 (30th July 2020)

• Record Type: Journal Article
• Authors: Zhu Chen, Johnny; Gao, Junxian; Probus, Paige R.; Liu, Wei; Wu, Xianli; Wegener, Evan C.; Kropf, A. Jeremy; Zemlyanov, Dmitry; Zhang, Guanghui; Yang, Xin; Miller, Jeffrey T.
• Is Part Of: Catalysis science & technology. Volume 10:Issue 17(2020)
• Page Start: 5973
• Page End: 5982
• Publication Date: 2020-07-30
• Subjects: Catalysis -- Periodicals; 541.395
• DOI: 10.1039/d0cy00897d
• Languages: English
• ISSNs: 2044-4753

Abstract

Abstract : The selectivity of Pt NP's (gray) are modified by SMSI oxides (red) leaving exposed small ensembles capable of dehydrogenation, but with limited activity for hydrogenolysis. Abstract : In this study, we show how strong metal–support interaction (SMSI) oxides in Pt–Nb/SiO2 and Pt–Ti/SiO2 affect the electronic, geometric and catalytic properties for propane dehydrogenation. Transmission electron microscopy (TEM), CO chemisorption, and decrease in the catalytic rates per gram Pt confirm that the Pt nanoparticles were partially covered by the SMSI oxides. X-ray absorption near edge structure (XANES), in situ X-ray photoelectron spectroscopy (XPS), and resonant inelastic X-ray scattering (RIXS) showed little change in the energy of Pt valence orbitals upon interaction with SMSI oxides. The catalytic activity per mol of Pt for ethylene hydrogenation and propane dehydrogenation was lower due to fewer exposed Pt sites, while turnover rates were similar. The SMSI oxides, however, significantly increase the propylene selectivity for the latter reaction compared to Pt/SiO2 . In the SMSI catalysts, the higher olefin selectivity is suggested to be due to the smaller exposed Pt ensemble sites, which result in suppression of the alkane hydrogenolysis reaction; while the exposed atoms remain active for dehydrogenation.