<scp>CO₂</scp> conversion through combined steam and <scp>CO₂</scp> reforming of methane reactions over Ni and Co catalysts

Abstract

Abstract Ni‐Co bimetallic and Ni or Co monometallic catalysts prepared for CO 2 reforming of methane were tested with the stimulated biogas containing steam, CO 2 , CH 4 , H 2 , and CO. A mix of the prepared CO 2 reforming catalyst and a commercial steam reforming catalyst was used in hopes of maximizing the CO 2 conversion. Both CO 2 reforming and steam reforming of CH 4 occurred over the prepared Ni‐Co bimetallic and Ni or Co monometallic catalysts when the feed contained steam. However, CO 2 reforming did not occur on the commercial steam reforming catalyst. There was a critical steam content limit above which the catalyst facilitated no more CO 2 conversion but net CO 2 production for steam reforming and water‐gas shift became the dominant reactions in the system. The Ni‐Co bimetallic catalyst can convert more than 70% of CO 2 in a biogas feed that contains ~33 mol% of CH 4 , 21.5 mol% of CO 2 , 12 mol% of H 2 O, 3.5 mol% of H 2 , and 30 mol% of N 2 . The H 2 /CO ratio of the produced syngas was in the range of 1.8‐2. X‐ray absorption spectroscopy of the spent catalysts revealed that the metallic sites of Ni‐Co bimetallic, Ni and Co monometallic catalysts after the steam reforming of methane reaction with equimolar feed (CH 4 :H 2 O:N 2 = 1:1:1) experienced severe oxidation, which led to the catalytic deactivation.