posted on 2020-11-17, 18:38authored byMaria Ronda-Lloret, Yaolin Wang, Paula Oulego, Gadi Rothenberg, Xin Tu, N. Raveendran Shiju
CO2 is a promising renewable, cheap, and abundant C1
feedstock for producing valuable chemicals, such as CO and methanol.
In conventional reactors, because of thermodynamic constraints, converting
CO2 to methanol requires high temperature and pressure,
typically 250 °C and 20 bar. Nonthermal plasma is a better option,
as it can convert CO2 at near-ambient temperature and pressure.
Adding a catalyst to such plasma setups can enhance conversion and
selectivity. However, we know little about the effects of catalysts
in such systems. Here, we study CO2 hydrogenation in a
dielectric barrier discharge plasma-catalysis setup under ambient
conditions using MgO, γ-Al2O3, and a series
of CoxOy/MgO
catalysts. While all three catalyst types enhanced CO2 conversion,
CoxOy/MgO
gave the best results, converting up to 35% of CO2 and
reaching the highest methanol yield (10%). Control experiments showed
that the basic MgO support is more active than the acidic γ-Al2O3, and that MgO-supported cobalt oxide catalysts
improve the selectivity toward methanol. The methanol yield can be
tuned by changing the metal loading. Overall, our study shows the
utility of plasma catalysis for CO2 conversion under mild
conditions, with the potential to reduce the energy footprint of CO2-recycling processes.