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The addition of platinum-group metals (PGMs, e.g., Pt) to CeO is used in heterogeneous catalysis to promote the rate of redox surface reactions. Well-defined model system studies have shown that PGMs facilitate H dissociation, H-spillover onto CeO surfaces, and CeO surface reduction. However, it remains unclear how the heterogeneous structures and interfaces that exist on powder catalysts influence the mechanistic picture of PGM-promoted H reactions on CeO surfaces developed from model system studies. Here, controlled catalyst synthesis, temperature-programmed reduction (TPR), in situ infrared spectroscopy (IR), and in situ electron energy loss spectroscopy (EELS) were used to interrogate the mechanisms of how Pt nanoclusters and single atoms influence H reactions on high-surface area Pt/CeO powder catalysts. TPR showed that Pt promotes H consumption rates on Pt/CeO even when Pt exists on a small fraction of CeO particles, suggesting that H-spillover proceeds far from Pt-CeO interfaces and across CeO-CeO particle interfaces. IR and EELS measurements provided evidence that Pt changes the mechanism of H activation and the rate limiting step for Ce, oxygen vacancy, and water formation as compared to pure CeO. As a result, higher-saturation surface hydroxyl coverages can be achieved on Pt/CeO compared to pure CeO. Further, Ce formed by spillover-H from Pt is heterogeneously distributed and localized at and around interparticle CeO-CeO boundaries, while activated H on pure CeO results in homogeneously distributed Ce. Ce localization at and around CeO-CeO boundaries for Pt/CeO is accompanied by surface reconstruction that enables faster rates of H consumption. This study reconciles the materials gap between model structures and powder catalysts for H reactions with Pt/CeO and highlights how the spatial heterogeneity of powder catalysts dictates the influence of Pt on H reactions at CeO surfaces.
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http://dx.doi.org/10.1021/jacsau.3c00330 | DOI Listing |
Langmuir
September 2025
Engineering Technology Research Center of Preparation and Application of Industrial Ceramics of Anhui Province, Engineering Research Center of High-frequency Soft Magnetic Materials and Ceramic Powder Materials of Anhui Province, School of Chemistry and Material Engineering, Chaohu University, Chaoh
In this study, a MoC-MoO@NCrGO-900 composite catalyst comprising two-dimensional nitrogen-doped reduced graphene oxide (NCrGO) and ultrasmall molybdenum carbide-molybdenum dioxide (MoC-MoO) heterojunctions was synthesized. The optimized catalyst exhibited an outstanding oxidative desulfurization (ODS) performance. Specifically, a model oil containing 4000 ppm sulfur was completely desulfurized within 30 min, with a desulfurization efficiency of 98.
View Article and Find Full Text PDFJ Am Chem Soc
September 2025
Beijing National Laboratory for Molecular Sciences, CAS Laboratory of Colloid and Interface and Thermodynamics, Center for Carbon Neutral Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
CO electroreduction to produce fuels and chemicals is of great significance. Molecular catalysts offer valuable advantages in light of their well-defined active sites and tunable structural and electronic properties. However, their stability is often compromised by rigid conjugated structures.
View Article and Find Full Text PDFRSC Adv
August 2025
Department of Chemistry, Faculty of Science, Cairo University Cairo Egypt
This study aims to valorize hazardous industrial marble machining and shaping waste powder as a precursor to prepare a heterogeneous nano-catalyst (CaO/KCO) employing the wet-impregnation method for producing biodiesel the transesterification of waste cooking oil (WCO). Surface and morphological characterization of the thus-prepared nano-catalyst has been performed employing various analytical tools, , XRD, BET, CO-TPD, FT-IR, HR-TEM, and FE-SEM & mapping EDX. The impact of calcination treatment on the catalytic performance is investigated together with the weight percentage (wt%) of CaO compared to KCO.
View Article and Find Full Text PDFChemphyschem
September 2025
School of Materials and Physics, China University of Mining and Technology, Xuzhou, 221116, China.
Advanced oxidation processes offer a potent, eco-friendly solution for degrading organic wastewater. Creating high-activity and stability catalysts is crucial to addressing water pollution concerns. Nevertheless, due to constraints in their preparation, prevalent catalysts often lack satisfactory cyclic stability and pose challenges in recovery.
View Article and Find Full Text PDFSci Rep
August 2025
Department of Chemistry, College of Science, King Faisal University, 31982, Al-Hassa, Saudi Arabia.
This study demonstrates the photocatalytic degradation efficiency of doped NiZnO and co-doped CdNiZnO NPs. Initially, ZnO NPs with a unique mesoporous ellipsoidal morphology were synthesized by simple precipitation and calcination. Powder X-ray diffraction revealed the formation of a hexagonal phase of the wurtzite structure.
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