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Strong metal–support interaction (SMSI) has gained great attention in the field of heterogeneous catalysis. However, whether single‐atom catalysts can exhibit SMSI remains unknown. Here, we demonstrate that SMSI can occur on TiO2‐supported Pt single atoms but at a much higher reduction temperature than that for Pt nanoparticles (NPs). Pt single atoms involved in SMSI are not covered by the TiO2 support nor do they sink into its subsurface. The suppression of CO adsorption on Pt single atoms stems from coordination saturation (18‐electron rule) rather than the physical coverage of Pt atoms by the support. Based on the new finding it is revealed that single atoms are the true active sites in the hydrogenation of 3‐nitrostyrene, while Pt NPs barely contribute to the activity since the NP sites are selectively encapsulated. The findings in this work provide a new approach to study the active sites by tuning SMSI. [ABSTRACT FROM AUTHOR]

Strong metal–support interaction (SMSI) has gained great attention in the field of heterogeneous catalysis. However, whether single‐atom catalysts can exhibit SMSI remains unknown. Here, we demonstrate that SMSI can occur on TiO2‐supported Pt single atoms but at a much higher reduction temperature than that for Pt nanoparticles (NPs). Pt single atoms involved in SMSI are not covered by the TiO2 support nor do they sink into its subsurface. The suppression of CO adsorption on Pt single atoms stems from coordination saturation (18‐electron rule) rather than the physical coverage of Pt atoms by the support. Based on the new finding it is revealed that single atoms are the true active sites in the hydrogenation of 3‐nitrostyrene, while Pt NPs barely contribute to the activity since the NP sites are selectively encapsulated. The findings in this work provide a new approach to study the active sites by tuning SMSI. [ABSTRACT FROM AUTHOR]

The factors that cause the instability of dye‐sensitized solar cells (DSSCs) remain to be elucidated. In this work, we focus on the light‐induced instability of N719 sensitizer that represents a large class of the ruthenium bipyridine sensitizers in DSSCs through in situ surface‐enhanced Raman spectroscopy (SERS) investigations. Systematic studies of surface plasmon‐driven reactions coupled with density functional theory (DFT) calculations clearly suggest the decarboxylation reaction induced by "hot electrons" generated on plasmonic metal surface as the reason for the instability. This decarboxylation reaction is also validated on TiO2 surface with the assistance of matrix‐assisted laser desorption/ionization time of flight mass spectrometry (MALDI‐TOF‐MS). This reaction is possibly the main reason leading to the inefficiency of N719 sensitization in DSSCs. Our findings may broaden the research scope of surface plasmon‐assisted catalytic reactions and provide insight into the optimal design of ruthenium based photosensitizers for DSSCs. The decarboxylation reaction of N719 molecules upon light illumination, which could be the main reason leading to the instability of DSSCs, was demonstrated by the in situ SERS technique. [ABSTRACT FROM AUTHOR]

Artificial photosynthesis requires the practical use of efficient, robust, and economical water-oxidation catalysts (WOCs) for chemical-fuel production. The synthesis of amorphous cobalt oxide nanoparticles (ca. 2 nm) is reported as a WOC with a turnover frequency up to 8.6 s−1 in the photocatalytic Ru(bpy)32+-Na2S2O8 system (bpy=2,2′-bipyridyl). This activity is unprecedented in heterogeneous cobalt-based WOCs and is even comparable to that of a state-of-the-art homogeneous cobalt-based polyoxometalate catalyst. With the help of experimental and computational X-ray absorption spectroscopy, the atomic structure of the synthesized amorphous cobalt oxide nanoparticles was characterized, and it consists of a one-dimensional chain of dimeric edge-sharing CoO6 octahedra. Theoretical calculations suggest that this structure was able to promote O−O bond coupling, unlike crystalline cobalt oxide WOCs, which led to the enhanced water-oxidation activity. [ABSTRACT FROM AUTHOR]

Strong metal–support interaction (SMSI) has gained great attention in the field of heterogeneous catalysis. However, whether single‐atom catalysts can exhibit SMSI remains unknown. Here, we demonstrate that SMSI can occur on TiO2‐supported Pt single atoms but at a much higher reduction temperature than that for Pt nanoparticles (NPs). Pt single atoms involved in SMSI are not covered by the TiO2 support nor do they sink into its subsurface. The suppression of CO adsorption on Pt single atoms stems from coordination saturation (18‐electron rule) rather than the physical coverage of Pt atoms by the support. Based on the new finding it is revealed that single atoms are the true active sites in the hydrogenation of 3‐nitrostyrene, while Pt NPs barely contribute to the activity since the NP sites are selectively encapsulated. The findings in this work provide a new approach to study the active sites by tuning SMSI. [ABSTRACT FROM AUTHOR]

Strong metal–support interaction (SMSI) has gained great attention in the field of heterogeneous catalysis. However, whether single‐atom catalysts can exhibit SMSI remains unknown. Here, we demonstrate that SMSI can occur on TiO2‐supported Pt single atoms but at a much higher reduction temperature than that for Pt nanoparticles (NPs). Pt single atoms involved in SMSI are not covered by the TiO2 support nor do they sink into its subsurface. The suppression of CO adsorption on Pt single atoms stems from coordination saturation (18‐electron rule) rather than the physical coverage of Pt atoms by the support. Based on the new finding it is revealed that single atoms are the true active sites in the hydrogenation of 3‐nitrostyrene, while Pt NPs barely contribute to the activity since the NP sites are selectively encapsulated. The findings in this work provide a new approach to study the active sites by tuning SMSI. [ABSTRACT FROM AUTHOR]