Abstract
The development of efficient Pd single-atom catalysts for CO oxidation, crucial for environmental protection and fundamental studies, has been hindered by their limited reactivity and thermal stability. Here, we report a thermally stable TiO2-supported Pd single-atom catalyst that exhibits enhanced intrinsic CO oxidation activity by tunning the local coordination of Pd atoms via H2 treatment. Our comprehensive characterization reveals that H2-treated Pd single atoms have reduced nearest Pd–O coordination and form short-distanced Pd–Ti coordination, effectively stabilizing Pd as isolated atoms even at high temperatures. During CO oxidation, partial replacement of the Pd–Ti coordination by O or CO occurs. This unique Pd local environment facilitates CO adsorption and promotes the activity of the surrounding oxygen species, leading to superior catalytic performance. Remarkably, the turnover frequency of the H2-treated Pd single-atom catalyst at 120 °C surpasses that of the O2-treated Pd single-atom catalyst and the most effective Pd/Pt single-atom catalysts by an order of magnitude. These findings open up new possibilities for the design of high-performance single-atom catalysts for crucial industrial and environmental applications.
Y. Lu, F. Lin, Z. Zhang, C. Thompson, Y. Zhu, N. Doudin, L. Kovarik, C.E. García Vargas, D. Jiang, J.L. Fulton, Y. Wu, F. Gao, Z. Dohnálek, A.M. Karim, H. Wang, Y. Wang, Enhancing activity and stability of pd-on-tio2 single-atom catalyst for low-temperature co oxidation through in situ local environment tailoring, Journal of the American Chemical Society, 2024. DOI: 10.1021/jacs.4c07861.
