Highly Active, Selective and Stable Reverse Water Gas Shift Catalyst Based on High Surface Area MoC/γ-Al2O3 Synthesized by Reverse Microemulsion

Abstract

The high surface area (190 m2/g) MoC/γ-Al2O3 catalyst with the MoC nanoparticle size of ca. 2 nm was synthesized via the reverse microemulsion method followed by the thermochemical treatment under CH4/H2 atmosphere. The catalytic performance of the MoC/γ-Al2O3 catalyst was evaluated for various temperatures and space velocities, in comparison to the MoC/γ-Al2O3 catalyst synthesized by wet precipitation and corresponding MoO3/γ-Al2O3 catalysts. All catalysts showed 100% selectivity to CO generation and CO2 conversions close to equilibrium for 500–600 °C (54–58% at 600 °C). Through the comprehensive characterization study, it has been found that the MoC/γ-Al2O3 catalyst synthesized via reverse microemulsions has the highest activity. Characterization study of spent catalysts has shown that MoO3/γ-Al2O3 is converted to MoC/γ-Al2O3 under the reaction conditions. Catalyst stability was evaluated for 100 h at 600 °C and 60,000 ml/(g h), showing that the reverse microemulsion-based MoC/γ-Al2O3 catalyst is the most stable, showing CO2 conversion of 59–60%, complete selectivity to CO formation and a negligible extent of carbon formation.