Cu-TM (Mn, Fe, Ni) dual-atom vs. Pt single atom: TM atoms modulate the electronic structure of Cu sites supported on melamine aerogel to enhance the catalytic purification performance of CH3SH

Abstract

Despite the high atomic utilization and unique electronic properties of single-atom catalysts (SACs), the single active site to some extent limits the rapid and stable execution of complex reactions involving multiple steps and intermediates on the SACs surface. To address this issue, dual-atom catalysts (DACs) have emerged. The specific spatial proximity enables a synergistic effect between the diatomic pairs, significantly promoting catalytic reactions, though the exact synergistic mechanisms remain to be explored. In this work, we successfully constructed Cu single-atom (Cu-MA) and CuTM (transition metal, TM = Mn, Fe, Ni) dual-atom (CuTM-MA) catalysts on the surface of melamine aerogel (MA) via the impregnation method. Additionally, single-atom catalysts with different Pt loadings (0.5 %, 1 %, and 2 %) (Pt-MA) were synthesized to compare the CH3SH decomposition activity with that of CuTM-MA. Experimental results showed that CuTM-MA significantly outperformed Cu-MA and even rivaled Pt-MA at high temperatures. Utilizing Cu K-edge XAFS, we found that the presence of TM not only enhanced the stability of Cu atoms on the MA surface, preventing aggregation at high temperatures to some extent, but also effectively modulated the electronic structure of Cu atoms, promoting electron transfer from Cu to TM, thus achieving a significant enhancement in catalytic activity.