Nitrogen-functionalized modulation of iron nanoparticles promotes selective hydrogenation of carbon dioxide

Abstract

Nitrogen-functionalized iron nanoparticles were prepared using a one-pot hydrothermal process. The utilization of urea as a nitrogen source during the hydrothermal process significantly influenced the morphology and defects of the obtained catalyst. Within an optimal range, the actual nitrogen promoter content could be controlled by altering the amount of urea introduced. The presence of a nitrogen promoter not only impacts catalytic activity but also plays a crucial role in product distribution. The FeC-N catalyst exhibited 32.0% selectivity toward light olefins, with a CO₂ conversion of 26.8%. The improvement in catalytic performance correlated with the specific surface area, dispersion of iron species, number of defect sites, and content of pyrrolic N species. Moreover, the enhanced selectivity for light olefins can be attributed to easier desorption from the FeC-N catalyst, thereby avoiding the over-hydrogenation of light olefins to paraffins.