Abstract

Here, MeFe-SiO2 (Me = Co, Ni, Pd, Pt) catalysts with bimetallic sites entrapped in a highly crystalline SiO2 structure were synthesized and used for the conversion of methane to olefins, aromatics, and hydrogen (MTOAH) at 1020°C. The MeFe-SiO2 catalysts showed polymorphic forms of cristobalite, quartz, and tridymite after reaction. Among the bimetallic catalysts, 0.5Pt1.0Fe-SiO2 exhibited the highest methane conversion (10.0%) with high hydrocarbon selectivity (79.9%) at 1020°C. In C2 (ethane, ethylene, acetylene) conversion with hydrogen co-feeding at 1020°C, acetylene was identified as a major coke precursor. MTOAH with different gas hourly space velocities (GHSV) showed that the 0.5Pt1.0Fe-SiO2 catalyst exhibited higher methane conversion and aromatics selectivity than the 1.0Fe-SiO2 catalyst. Density functional theory calculations showed that the Pt-Fe3C surface is energetically favorable for methane activation and inhibits graphitic coke deposition by C2 dehydrogenation. Consequently, a modification of the entrapped Fe sites by Pt addition improved the methane conversion and hydrocarbon selectivity of the catalyst.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.