Nanocatalyst Engineering via Metal Ion Doping: Regulating Rate-Determining Steps for Stable Ozone Decomposition

Catalyst deactivation in ozone decomposition reactions primarily results from the accumulation of intermediate oxygen species at surface oxygen vacancies due to limitations in the rate-determining step. This study demonstrates a valence-state engineering strategy to regulate this process through metal ion doping (Li+, Mg2+, Al3+) in NiO nanocatalysts. By modulating the work function and electron-donating capacity of NiO via controlled doping, we successfully alleviated the limitation imposed by the rate-determining step in ozone decomposition, effectively mitigating catalyst deactivation. Notably, low-valence Li+ doping increases the work function, exacerbates the limitations of the rate-determining step, and accelerates deactivation. While doping with high-valent Al3+ significantly reduces the work function, lessens the influence of the rate-determining step, and enhances catalytic activity. Comparative studies with Co3O4/Li–Co3O4 and MnO2/Li–MnO2 systems further reveal that identical dopants can produce opposing effects on activity, depending on the specific rate-determining step of the catalytic process. These findings provide fundamental insights into the relationship between electronic structure and catalytic performance, offering a design strategy for developing stable, high-efficiency ozone decomposition catalysts.