Middle pressure methane conversion into C_2 hydrocarbons on supported Pt-Co catalysts

摘要

Pt-Co bimetallic catalysts were prepared by incipient wetness technique on alumina or NaY zeolite and were characterized by XRF, XRD, TPR, CO chemisorption and X-ray photoelectron spectroscopy. Methane conversion to higher hydrocarbons was investigated in a flow system by high temperature one-step, constant flow mode at 750℃ and by two-step low temperature pulse mode at 250℃ under non-oxidative conditions. Catalytic activity in oxygen-free transformations at atmospheric pressure is stable only for a short time. The simultaneous use of higher pressure and high temperature weakens the poisoning effect and makes the process possible to form primarily ethane (and ethene) which is predicted from thermodynamic calculations. The nature of support also significantly affects the amount of C_(2+) products, which can be attributed to structural differences of metal particles (location, reducibility, dispersion).