Abstract
In this study, a series of novel Pt–Ni bimetallic catalysts supported on LaFeO3/SiO2 with different amounts of Ni were prepared by the lattice atomic-confined reduction of LaFe1−x(Ni, Pt)xO3/SiO2 perovskite precursors and applied in isobutane dehydrogenation to isobutene reaction. The catalysts were characterized by X-ray diffraction, H2-temperature-programmed reduction, Brunauer–Emmett–Teller analysis, transmission electron microscopy, energy dispersive X-ray, CO chemisorption, X-ray photoelectron spectroscopy, and thermogravimetric analysis. The as-synthesized Pt–Ni bimetallic catalysts possessed smaller most probable particle size with tunable Pt–Ni interaction, depending on the Ni content. The catalyst with Ni content of 3.0 wt% showed excellent activity and stability (the isobutane conversion and isobutene selectivity remained at about 38% and 92%, respectively, after 310 min) for the isobutane dehydrogenation reaction. It also provided approximately six times turnover frequency of the catalyst without Ni. The excellent activity and stability of the 3.0 wt% Ni-containing catalyst can be attributed to its small metal nanoparticles with high dispersion and suitable Pt–Ni interaction. Moreover, the Pt(Ni)–LaFeO3/SiO2 catalyst with Ni content of 3.0 wt% had been run for more than 35 h without obvious loss of activity, indicating its long-term stability, and the decrease in the Pt–Ni interaction that accompanied the formation of the FeNi alloy phase was thought to be responsible for the slight decrease in activity.
Highlights
Olefins, especially isobutene, are indispensable chemical raw materials for producing commodities such as plastic, fiber, and rubber [1]
A series of Pt–Ni bimetallic catalysts supported on La2O3–LaFeO3/SiO2 with different amounts of Ni were prepared by the lattice atomic-confined reduction of SiO2-supported LaFe1−x(Ni, Pt)xO3 perovskite-type oxide (PTO) precursors
It can be deduced that the small LaFe1−x(Ni, Pt)xO3 NPs with PTOs structures have been successfully loaded on the SiO2
Summary
Especially isobutene, are indispensable chemical raw materials for producing commodities such as plastic, fiber, and rubber [1]. This can be explained by the fact that (1) all the metal NPs are derived from the corresponding metallic ions confined in the PTO lattices, in which each metal element must be uniformly dispersed at the atomic level; (2) during reduction, an interaction between the metallic particles and remaining PTO results in small NP sizes; and (3) meso–macropore SiO2 with a high surface area provides a platform for the uniform dispersion of metal particles.
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