The d-band center from transition metals on platinum-based catalysts for enhanced toluene oxidation

Substitution or reducing the amount of Pt by using non-precious transition metals (TM) in a catalyst is a feasible strategy for commercial viability. However, the synergistic mechanism between PtTM remains unclear. In this work, we thoroughly investigated the catalytic activity of PtTM (TM = Mn, Fe, Co, Ni, Cu, or Zn) bimetal catalysts for toluene oxidation, using a covalent triazine framework (CTF-1) as a substrate. Notably, PtMn/CTF-1 exhibited excellent catalytic activity and long-term stability for toluene oxidation. Density functional theory combined with the d-band theory calculations indicate that the catalytic activity depends on oxygen activation. Compared to pure Pt, PtMn shows the largest shift of the d-band center due to the influence of Mn, which significantly increases the Fermi level after O₂ adsorption and generates activated O₂ with highly asymmetric spin states. The theoretical calculations and experimental results provide deep insights into the relationship between PtMn/CTF-1 structure and catalytic activity, which holds significant implications for future design and applications of Pt-based alloy catalysts.