Hydrogenation of
carbon dioxide to value-added chemicals and fuels
has recently gained increasing attention as a promising route for
utilizing carbon dioxide to achieve a sustainable society. In this
study, we investigated the hydrogenation of CO2 over M/SiO2 and M/Al2O3 (M = Co, Ni) catalysts
in a dielectric barrier discharge system at different temperatures.
We compared three different reaction modes: plasma alone, thermal
catalysis, and plasma catalysis. The coupling of catalysts with plasma
demonstrated synergy at different reaction temperatures, surpassing
the thermal catalysis and plasma alone modes. The highest CO2 conversions under plasma-catalytic conditions at reaction temperatures
of 350 and 500 °C were achieved with a Co/SiO2 catalyst
(66%) and a Ni/Al2O3 catalyst (68%), respectively.
Extensive characterizations were used to analyze the physiochemical
characteristics of the catalysts. The results show that plasma power
was more efficient than heating power at the same temperature for
the CO2 hydrogenation. This demonstrates that the performance
of CO2 hydrogenation can be significantly improved in the
presence of plasma at lower temperatures.