Tunning Pd local environments for catalytic oxidation of light VOCs and CO: influence of Ce addition

The geometric interplay in heterogeneous catalysis plays a crucial role in determining the catalytic performance. Based on the stronger affinity of Pd for ceria (CeO 2 ) than for titanium oxide (TiO 2 ) found in this work, we strategically engineered distinct Pd local environments by controlling the architecture of CeO x on TiO 2 through adjusting Ce content. At low Ce content, Pd preferentially assembles onto CeO x islands that are interspersed on TiO 2 ; while at high Ce content, Pd predominantly anchors onto the extensive CeO x surface. The former structure, enriched with CeO x -TiO 2 interface, exhibits superior capability in C-H bond cleavage and O 2 activation, leading to outstanding performance in the oxidation of carbon-containing gases such as light volatile organic compounds (VOCs; e.g., ethane and ethylene) and carbon monoxide (CO). In contrast, the structure dominated by continuous CeO 2 networks shows markedly lower activity. Combined analyses indicate that Pd 2+ species act as the primary active sites, and the consistent activity trend across differently Ce-modified catalysts in VOCs and CO oxidation can be explained by shared mechanistic steps, particularly through common CO and bicarbonate species intermediates. This work provides fundamental insight into the relationship between interfacial geometry and catalytic function.