Structural evolution of atomically dispersed Pt catalysts dictates reactivity

The use of oxide-supported isolated Pt-group metal atoms as catalytic active sites is of interest due to their unique reactivity and efficient metal utilization. However, relationships between the structure of these active sites, their dynamic response to environments and catalytic functionality have proved difficult to experimentally establish. Here, sinter-resistant catalysts where Pt was deposited uniformly as isolated atoms in well-defined locations on anatase TiO2 nanoparticle supports were used to develop such relationships. Through a combination of in situ atomic-resolution microscopy- and spectroscopy-based characterization supported by first-principles calculations it was demonstrated that isolated Pt species can adopt a range of local coordination environments and oxidation states, which evolve in response to varied environmental conditions. The variation in local coordination showed a strong influence on the chemical reactivity and could be exploited to control the catalytic performance.Oxide-supported isolated Pt-group metal atoms as catalytic active sites are of interest because of their unique reactivity. Isolated Pt species are now shown to adopt a range of local coordination environments and oxidation states in response to environmental conditions.

[1]  Konstantin M. Neyman,et al.  Can the state of platinum species be unambiguously determined by the stretching frequency of an adsorbed CO probe molecule? , 2016, Physical chemistry chemical physics : PCCP.

[2]  F Mittendorfer,et al.  Accurate surface and adsorption energies from many-body perturbation theory. , 2010, Nature materials.

[3]  G. Kresse,et al.  From ultrasoft pseudopotentials to the projector augmented-wave method , 1999 .

[4]  Blöchl,et al.  Projector augmented-wave method. , 1994, Physical review. B, Condensed matter.

[5]  R. Gorte,et al.  Study of CO Oxidation Kinetics on Rh/Ceria , 1995 .

[6]  G. Stucky,et al.  Supplementary Material for Identification of active sites in CO oxidation and water-gas shift over supported Pt catalysts , 2015 .

[7]  Xiaoqing Pan,et al.  In situ atomic-scale observation of oxygen-driven core-shell formation in Pt3Co nanoparticles , 2017, Nature Communications.

[8]  Ulrike Diebold,et al.  Carbon monoxide-induced adatom sintering in a Pd-Fe3O4 model catalyst. , 2013, Nature materials.

[9]  Marcel Schreier,et al.  A fundamental study of Pt tetraammine impregnation of silica: 1. The electrostatic nature of platinum adsorption , 2004 .

[10]  D. Dixon,et al.  Beating Heterogeneity of Single-Site Catalysts: MgO-Supported Iridium Complexes , 2018 .

[11]  Burke,et al.  Generalized Gradient Approximation Made Simple. , 1996, Physical review letters.

[12]  Xiaoqing Pan,et al.  Adsorbate-mediated strong metal-support interactions in oxide-supported Rh catalysts. , 2017, Nature chemistry.

[13]  Qinghua Zhang,et al.  Direct observation of noble metal nanoparticles transforming to thermally stable single atoms , 2018, Nature Nanotechnology.

[14]  K. Burke,et al.  Generalized Gradient Approximation Made Simple [Phys. Rev. Lett. 77, 3865 (1996)] , 1997 .

[15]  C. Peden,et al.  Kinetics of CO oxidation on single-crystal Pd, Pt, and Ir , 1988 .

[16]  Xiaoqing Pan,et al.  Combining In-Situ Transmission Electron Microscopy and Infrared Spectroscopy for Understanding Dynamic and Atomic-Scale Features of Supported Metal Catalysts , 2018, The Journal of Physical Chemistry C.

[17]  张涛,et al.  Single-atom catalysis of CO oxidation using Pt1 FeOx , 2011 .

[18]  M. Daturi,et al.  FTIR spectroscopy study of CO and NO adsorption and co-adsorption on Pt/TiO2 , 2007 .

[19]  Avelino Corma,et al.  Metal Catalysts for Heterogeneous Catalysis: From Single Atoms to Nanoclusters and Nanoparticles , 2018, Chemical reviews.

[20]  A V Crewe,et al.  Visibility of Single Atoms , 1970, Science.

[21]  Ulrike Diebold,et al.  CO Induced Adatom Sintering in a Model Catalyst: Pd/Fe3O4 , 2013, 1303.0664.

[22]  S. C. Parker,et al.  The Effect of Size-Dependent Nanoparticle Energetics on Catalyst Sintering , 2002, Science.

[23]  Vanessa N Yang,et al.  Isolated metal active site concentration and stability control catalytic CO2 reduction selectivity. , 2015, Journal of the American Chemical Society.

[24]  S. C. Fung,et al.  Strong metal-support interactions. Group 8 noble metals supported on titanium dioxide , 1978 .

[25]  F. Ribeiro,et al.  Dynamic multinuclear sites formed by mobilized copper ions in NOx selective catalytic reduction , 2017, Science.

[26]  G. Pacchioni,et al.  Adsorption of Ruthenium Atoms and Clusters on Anatase TiO2 and Tetragonal ZrO2(101) Surfaces: A Comparative DFT Study , 2015 .

[27]  Raul Arenal,et al.  Generation of subnanometric platinum with high stability during transformation of a 2D zeolite into 3D. , 2017, Nature materials.

[28]  Michelle H. Wiebenga,et al.  Thermally stable single-atom platinum-on-ceria catalysts via atom trapping , 2016, Science.

[29]  Xiaoqing Pan,et al.  Quantitative and Atomic-Scale View of CO-Induced Pt Nanoparticle Surface Reconstruction at Saturation Coverage via DFT Calculations Coupled with in Situ TEM and IR. , 2017, Journal of the American Chemical Society.

[30]  M. Flytzani-Stephanopoulos,et al.  Active Nonmetallic Au and Pt Species on Ceria-Based Water-Gas Shift Catalysts , 2003, Science.

[31]  S. Bent,et al.  In situ observation of phase changes of a silica-supported cobalt catalyst for the Fischer-Tropsch process by the development of a synchrotron-compatible in situ/operando powder X-ray diffraction cell. , 2018, Journal of synchrotron radiation.

[32]  G. Kresse,et al.  Efficiency of ab-initio total energy calculations for metals and semiconductors using a plane-wave basis set , 1996 .

[33]  A. Corma,et al.  Reversible Transformation of Pt Nanoparticles into Single Atoms inside High-Silica Chabazite Zeolite. , 2016, Journal of the American Chemical Society.

[34]  Xiaofeng Yang,et al.  Single-atom catalysis of CO oxidation using Pt1/FeOx. , 2011, Nature chemistry.

[35]  R. Prins,et al.  Structure of rhodium in an ultradispersed Rh/Al2O3 catalyst as studied by EXAFS and other techniques , 1985 .

[36]  M. Flytzani-Stephanopoulos,et al.  Atomically dispersed supported metal catalysts. , 2012, Annual review of chemical and biomolecular engineering.

[37]  Robert Schlögl,et al.  CO oxidation as a prototypical reaction for heterogeneous processes. , 2011, Angewandte Chemie.

[38]  Ulrike Diebold,et al.  One Step Towards Bridging the Materials Gap: Surface Studies of TiO2 Anatase , 2003 .

[39]  Kazuhiro Takanabe,et al.  Chemisorption of CO and mechanism of CO oxidation on supported platinum nanoclusters. , 2011, Journal of the American Chemical Society.

[40]  P. Redhead.  Thermal desorption of gases , 1962 .

[41]  E. Sykes,et al.  An atomic-scale view of single-site Pt catalysis for low-temperature CO oxidation , 2018, Nature Catalysis.

[42]  G. Pacchioni,et al.  Nature of stable single atom Pt catalysts dispersed on anatase TiO2 , 2018, Journal of Catalysis.

[43]  M Newville,et al.  ATHENA, ARTEMIS, HEPHAESTUS: data analysis for X-ray absorption spectroscopy using IFEFFIT. , 2005, Journal of synchrotron radiation.

[44]  E. Stach,et al.  Dynamic restructuring drives catalytic activity on nanoporous gold-silver alloy catalysts. , 2017, Nature materials.

[45]  J. Grunwaldt,et al.  Tuning the Structure of Platinum Particles on Ceria In Situ for Enhancing the Catalytic Performance of Exhaust Gas Catalysts. , 2017, Angewandte Chemie.

[46]  G. Pacchioni,et al.  A DFT study of the acid–base properties of anatase TiO2 and tetragonal ZrO2 by adsorption of CO and CO2 probe molecules , 2016 .

[47]  P. Christopher,et al.  Utilizing Quantitative in Situ FTIR Spectroscopy To Identify Well-Coordinated Pt Atoms as the Active Site for CO Oxidation on Al2O3-Supported Pt Catalysts , 2016 .

[48]  Konstantin M. Neyman,et al.  Maximum noble-metal efficiency in catalytic materials: atomically dispersed surface platinum. , 2014, Angewandte Chemie.

[49]  Piyasan Praserthdam,et al.  A single-site platinum CO oxidation catalyst in zeolite KLTL: microscopic and spectroscopic determination of the locations of the platinum atoms. , 2014, Angewandte Chemie.

[50]  W. Sachtler,et al.  Identification of isolated Pt atoms in H-mordenite , 1994 .

[51]  C. Catlow,et al.  Oxidation states and ionicity , 2018, Nature Materials.

[52]  S. J. Tauster.  Strong metal-support interactions , 1986 .

[53]  Xiaoqing Pan,et al.  Catalyst Architecture for Stable Single Atom Dispersion Enables Site-Specific Spectroscopic and Reactivity Measurements of CO Adsorbed to Pt Atoms, Oxidized Pt Clusters, and Metallic Pt Clusters on TiO2. , 2017, Journal of the American Chemical Society.

[54]  B. Gates,et al.  Homogeneity of Surface Sites in Supported Single-Site Metal Catalysts: Assessment with Band Widths of Metal Carbonyl Infrared Spectra. , 2016, The journal of physical chemistry letters.