Promoting intermediates transformation by boosting H₂O dissociation over core-shell Pd@CoO Janus for acetone efficacious oxidation

Reactivity loss by intermediates aggregation and water vapor inhibition are two major and longstanding challenges for the noble-metal-based catalysts in oxygenated volatile organic compounds (OVOCs) oxidation. Herein, the core-shell Pd@CoO Janus sites are creatively designed and stabilized over the HSAPO-34 support. Quasi in situ XPS spectra reveal that the strong interactions in Pd@CoO Janus sites promote the charge redistribution and electron back-donation through Pd-O-Co coordination. Therefore, abundant positively charged Pd²⁺ sites are formed and oxygen species transformation is facilitated, which significantly promote the low-temperature efficiency of acetone oxidation. Furthermore, the Pd@CoO/HSAPO-34 catalyst facilitates H₂O molecules dissociation and produce reactive OH_Ter and OH_Tri species, which considerably promotes the rapid decomposition of aldehyde intermediate via attacked CH₂O* group, ensuring low-temperature oxidation of acetone. This work provides valuable guidance to develop specific catalysts with functional active sites for rationally utilizing H₂O molecules to improve low-temperature performance and modulate reaction pathways during OVOCs oxidation.