Effect of magnetic field on CO2 conversion over Cu-ZnO/ZrO2 catalyst in hydrogenation reaction

• Magnetic field intensity and orientation affected activity of Cu-ZnO/ZrO2 catalyst.
• Activation energy with magnetic field was lower than that of w/o magnetic field.
• Magnetic field reduced operating temperature and CO2 emission during the reaction.
• Magnetic field-assisted system was green and carbon-neutral CO2 conversion process.

Based on green and sustainable innovation with efficient utilization concepts for enhancement of catalyst performance and energy conservation, an external magnetic field has been applied in CO2 hydrogenation reaction in order to improve catalytic activity and reduce the energy consumption. In this research, the performances of Cu-ZnO/ZrO2 catalyst under magnetic field with different magnetic field intensities (0, 20.8, and 27.7 mT) and orientations (north-to-south (N-S) and south-to-north (S-N) directions) in CO2 hydrogenation were investigated. Cu-ZnO/ZrO2 catalysts operated under magnetic field gave higher CO2 conversions, compared to that of without magnetic field at all reaction temperatures. The highest CO2 conversions were obtained under the magnetic field condition at 20.8 mT in S-N direction which was 1.8–3.0 times higher than that of without magnetic field. Accordingly, the operating temperatures were significantly lower than those of without magnetic field at the same reaction rate. This outstanding performance could be attributed to the fact that the external magnetic field facilitated adsorption of CO2 reactant gas molecules over the surface of magnetized catalysts. Accordingly, the challenge in application of magnetic field in CO2 hydrogenation process help reduce CO2 emission into the atmosphere compared to the convention reactor, and therefore led to the carbon-neutral CO2 conversion process.