Stretched Pd-CoO_x Interfaces-Induced Oxygen Vacancy Consecutive Activation Realizes Light Alkane Efficacious Destruction

The introduction of oxygen vacancies (O_v) into catalyst structures has proven to be an effective strategy for enhancing their activity. To maintain their catalytic performance, however, the efficacious replenishing of the continuously depleted O_v during reactions is pivotal and still a great challenge. To address this, a Pd-CoO_x/CeO₂ catalyst (Pd-Ens) with highly exposed Pd-CoO_x interfaces was rationally crafted, over which remarkable propane degradation activity, stability, and SO₂ resistance can be obtained owing to high Pd²⁺ ratio and significant O_v content. The exposed Pd-CoO_x interfaces stretched the lattice of Pd-Ens catalyst, which boosts the redox capacity and charge transfer ability, facilitating the activation of lattice oxygen (O_lat) for O_v generation and subsequently stabilizing the Pd species. Continuous O_lat activation and abundant O_v promote the adsorption and activation of propane and oxygen over Pd-Ens, accelerating the formation of the acetone intermediate while expediting subsequent deep oxidation. Moreover, the adsorption of SO₂ impurity is well limited over Pd-Ens surface attributing to the existence of Pd-CoO_x interfaces. In comparison, the Pd-Sup2 counterpart with internal PdO/Co₃O₄ interfaces exhibits inferior propane catalytic performance and SO₂ resistance due to the irreversible O_v depletion, extensive Pd species oxidation, and strong SO₂ adsorption. Besides, the weak mineralization ability makes Pd-Sup2 yield more harmful byproducts. These findings offer crucial guidance for developing efficient and practicable catalysts for light alkane degradation as well as other heterogeneous oxidation reactions.