Abstract Monolithic SiC-foam-structured Mn2O3-Na2WO4-TiO2 catalysts are developed via a binder-free dip-coating method for the oxidative coupling of methane reaction. MnTiO3-assisted growth of coating from nanoparticles to nanorods proceeds spontaneously to… Click to show full abstract
Abstract Monolithic SiC-foam-structured Mn2O3-Na2WO4-TiO2 catalysts are developed via a binder-free dip-coating method for the oxidative coupling of methane reaction. MnTiO3-assisted growth of coating from nanoparticles to nanorods proceeds spontaneously to form interpenetrating nano-structure in the presence of alkali (such as Na2WO4) during the high-temperature calcination treatment, which grants the coating strong robustness. This catalyst involves the effective and efficient coupling of advanced catalysis of Mn2O3-Na2WO4-TiO2 coating with enhanced heat/mass transfer stemmed from SiC-foam substrate. The preferred catalyst is the one with 40 wt% coating at Mn2O3/Na2WO4/TiO2 weight ratio of 2.2%/5.1%/32.7%, giving 26% CH4 conversion and 69% C2-3 selectivity at 800 °C and 0.1 MPa for a feed gas of CH4/O2 of molar ratio of 5/1 at gas hourly space velocity of 4000 h−1. The SiC-foam-structured Mn2O3-Na2WO4-TiO2 catalyst can also be used for this reaction in the form of bead string reactor, and the highest C2-3 yield of 13% is obtained with 18% CH4 conversion and 72% C2-3 selectivity at 0.35 MPa, 20,000 h−1, CH4/O2 molar ratio of 6.5/1, and 800 °C.
               
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