Unraveling the advantages of Pd/CeO2 single-atom catalysts in the NO + CO reaction by model catalysts

Integrating Atomically Dispersed Sites with Versatile Oxide Supports to Construct Efficient Thermocatalysts: Toward Comprehensive Treatment of Flue Gas Pollutants

“…110 In the recent study by Ji et al, 111 the state density of the Pt d orbitals in the Pt 1 −CuO/ CoAlO shifted toward the Fermi level, which reinforced the interaction between the catalyst and adsorbed intermediates, contributing the 91% NO conversion at 200 °C under 3 vol % O 2 (Figure 7e). This was consistent with the research of Xu et al 108 Notably, the construction of dinuclear functional sites in CO-SCR catalysts has attracted an extensive amount of interest from researchers. For instance, Liu et al 112 anchored dual active centers of Co 1 and cluster CoO x on Ce 0.75 Zr 0.25 O 2 , where the CoO x cluster improved the conversion of NO to nitrate intermediates (e.g., linear NO 2− and free NO 3− ); the Co 1 promoted the CO adsorption, which could reduce the surface-active oxygen species and contribute to the reduction of intermediates.…”

“…As reported by Xu et al, 108 the Pd 1 /CeO 2 exhibited more superior catalytic behaviors than the corresponding Pd NP / CeO 2 in CO-SCR, due to more Pd 2+ state over Pd 1 /CeO 2 (Figure 7a). Notably, as displayed in Figure7b,c, the byproduct N 2 O was only observed in Pt NP /CeO 2 , which could be attributed to the difference in NO dissociation behavior at high temperatures.…”

“…(d) In situ DRIFT spectra on Pt 1 /CeO 2 . Reproduced with permission from ref . Copyright 2023, Springer Nature.…”

Synergy of Single-Atom Fe1 and Ce–Ov Sites on Mesoporous CeO2–Al2O3 for Efficient Selective Catalytic Reduction of NO with CO

“…Noble metal catalysts, such as Pt, , Rh, , Pd, , Ir, , Ru, or their alloys − are widely recognized as the most promising candidates. However, the N 2 selectivity of noble metal catalysts is usually not satisfactory.…”

“…Deep oxidation of NO is difficult to avoid due to the strong oxidation ability of noble metals. − One other explanation could be a different reaction pathway defined by the coexistence of different types of metal sites, ,− including single atoms, clusters, nanoparticles, and oxides. Recently, single-atom catalysts have drawn a lot of interest for their uniform local structure and maximized atom utilization, which enables extraordinary activity and excellent selectivity. , The uniformity of the single-atom sites shows potential for enhancing the selectivity of noble metal catalysts for the NO–CO reaction. ,,,, However, the utilization of these noble metal catalysts still suffers from the expensive consumption of noble metals, which results in a high cost for the abatement of NO x .…”