Enlarging the Three-Phase Boundary to Raise CO₂/CH₄ Conversions on Exsolved Ni–Fe Alloy Perovskite Catalysts by Minimal Rh Doping

Abstract

Exsolved Ni−Fe alloy perovskite catalysts exhibit remarkable coking resistance during C−H and C−O activation. However, metallic utilization is typically incomplete, resulting in relatively low catalytic activity. Herein, we investigated minimal doping with Rh to boost the catalytic activity in the dry reforming of methane by promoting exsolution and enlargement of the three-phase boundary between the alloy, support, and reactants. The Rh influences the formation of the Ni−Fe alloy, as revealed by X-ray diffraction, and promotes the individual and collective CH 4 and CO 2 conversions, as revealed by packed bed reactor runs, temperature-programmed surface reactions, and in situ infrared spectroscopy. A minimal 0.21 wt % Rh addition enlarges the three-phase boundary while improving oxygen mobility and storage. The oxygen mobility is responsible for promoting CH 4 dissociation and dynamic removal of carbon-containing intermediates, such that the catalyst remains stable for over 100 h under both 1 and 14 bar.

Efficient and Stable Production of Long-Chain Hydrocarbons over Hydrophobic Carbon-Encapsulated TiO2-Supported Ru Catalyst in Fischer–Tropsch Synthesis

“…The depletion of global oil reserves has sparked concerns about the future production of essential petrochemicals and fuels. Fischer–Tropsch synthesis (FTS) is a promising technology that converts syngas, a mixture of CO and H 2 , from various nonpetroleum-based sources (i.e., natural gas, coal, and biomass) into liquid fuels. − Among FTS catalysts, ruthenium (Ru)-based catalysts have demonstrated higher activity and selectivity toward the production of heavy hydrocarbons than iron (Fe)- and cobalt (Co)-based catalysts . However, maintaining the high performance of Ru-based catalysts under high-pressure and high-temperature operation conditions is still a significant challenge due to the agglomeration of metal nanoparticles (NPs) over time, resulting in catalyst sintering and deactivation.…”