Catalyst Engineering for the Selective Reduction of CO <sub>2</sub> to CH <sub>4</sub> : A First‐Principles Study on X‐MOF‐74 (X=Mg, Mn, Fe, Co, Ni, Cu, Zn)
Gavin A. McCarver, Taner Yildirim, Wei Zhou
Abstract
Abstract The conversion of carbon dioxide (CO 2 ) into more valuable chemical compounds represents a critical objective for addressing environmental challenges and advancing sustainable energy sources. The CO 2 reduction reaction (CO 2 RR) holds promise for transforming CO 2 into versatile feedstock materials and fuels. Leveraging first‐principles methodologies provides a robust approach to evaluate catalysts and steer experimental efforts. In this study, we examine the CO 2 RR process using a diverse array of representative cluster models derived from X‐MOF‐74 (where X encompasses Mg, Mn, Fe, Co, Ni, Cu, or Zn) through first‐principles methods. Notably, our investigation highlights the Fe‐MOF‐74 cluster's unique attributes, including favorable CO 2 binding and the lowest limiting potential of the studied clusters for converting CO 2 to methane (CH 4 ) at 0.32 eV. Our analysis identified critical factors driving the selective CO 2 RR pathway, enabling the formation CH 4 on the Fe‐MOF‐74 cluster. These factors involve less favorable reduction of hydrogen to H 2 and strong binding affinities between the Fe open‐metal site and reduction intermediates, effectively curtailing desorption processes of closed‐shell intermediates such as formic acid (HCOOH), formaldehyde (CH 2 O), and methanol (CH 3 OH), to lead to selective CH 4 formation.