Single-atom Pd₁O₄Ce₂/CeO₂ catalyst with unique local fields for methane-catalyzed combustion

Modifying the local fields of active metals can directly and effectively optimize the catalytic performance in the heterogeneous catalytic process. Here, the local fields of single-atom Pd in the Pd₁/CeO₂ catalyst were tailored by using a self-sacrificial electron-rich carbon nitride to obtain the Pd₁O₄Ce₂/CeO₂ with coordination unsaturated single-atom Pd. Compared with Pd₁O₄Ce₃/CeO₂ with coordination saturated single-atom Pd, the Pd₁O₄Ce₂/CeO₂ catalyst showed enhanced activity for CH₄ combustion with decreased 118 °C of T₅₀ and 8 times higher in turnover frequency (TOF) at 400 °C. The thermal decomposition of carbon nitride pre-coordinated Pd created a unique atmosphere around Pd species, leading to the formation of coordination unsaturated single-atom Pd on the surface of CeO₂. This coordination unsaturated single-atom Pd catalyst conduced to the polarization of CH₄ and reduced the cleavage energy barrier of CH₄, thus accelerating the catalytic activity. The construction method of this coordination unsaturated structure provides insights for the designing and synthesizing of highly active single atom catalysts.