title: Elucidation of peptide-directed palladium surface structure for biologically tunable nanocatalysts.
abstract: Peptide-enabled synthesis of inorganic nanostructures represents an avenue to access catalytic materials with tunable and optimized properties. This is achieved via peptide complexity and programmability that is missing in traditional ligands for catalytic nanomaterials. Unfortunately, there is limited information available to correlate peptide sequence to particle structure and catalytic activity to date. As such, the application of peptide-enabled nanocatalysts remains limited to trial and error approaches. In this paper, a hybrid experimental and computational approach is introduced to systematically elucidate biomolecule-dependent structure/function relationships for peptide-capped Pd nanocatalysts. Synchrotron X-ray techniques were used to uncover substantial particle surface structural disorder, which was dependent upon the amino acid sequence of the peptide capping ligand. Nanocatalyst configurations were then determined directly from experimental data using reverse Monte Carlo methods and further refined using molecular dynamics simulation, obtaining thermodynamically stable peptide-Pd nanoparticle configurations. Sequence-dependent catalytic property differences for C-C coupling and olefin hydrogenation were then elucidated by identification of the catalytic active sites at the atomic level and quantitative prediction of relative reaction rates. This hybrid methodology provides a clear route to determine peptide-dependent structure/function relationships, enabling the generation of guidelines for catalyst design through rational tailoring of peptide sequences.
authors.affiliation: †Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433, United States.|‡Department of Chemistry, University of Miami, Coral Gables, Florida 33146, United States.
authors.forename: Nicholas M
authors.initials: NM
authors.lastname: Bedford
authors.affiliation: §Department of Polymer Engineering, University of Akron, Akron, Ohio 44325, United States.
authors.forename: Hadi
authors.initials: H
authors.lastname: Ramezani-Dakhel
authors.affiliation: †Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433, United States.
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Slocik
authors.affiliation: ‡Department of Chemistry, University of Miami, Coral Gables, Florida 33146, United States.
authors.forename: Beverly D
authors.initials: BD
authors.lastname: Briggs
authors.affiliation: ⊥X-ray Science Division, Argonne National Laboratory, Argonne, Illinois 60439, United States.
authors.forename: Yang
authors.initials: Y
authors.lastname: Ren
authors.affiliation: ∥Department of Physics, Yeshiva University, New York, New York 10016, United States.
authors.forename: Anatoly I
authors.initials: AI
authors.lastname: Frenkel
authors.affiliation: #Department of Physics, Central Michigan University, Mt. Pleasant, Michigan 48858, United States.
authors.forename: Valeri
authors.initials: V
authors.lastname: Petkov
authors.affiliation: §Department of Polymer Engineering, University of Akron, Akron, Ohio 44325, United States.
authors.forename: Hendrik
authors.initials: H
authors.lastname: Heinz
authors.affiliation: †Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433, United States.
authors.forename: Rajesh R
authors.initials: RR
authors.lastname: Naik
authors.affiliation: ‡Department of Chemistry, University of Miami, Coral Gables, Florida 33146, United States.
authors.forename: Marc R
authors.initials: MR
authors.lastname: Knecht
mesh_terms: D000475:Alkenes / Q000737:chemistry; D000595:Amino Acid Sequence; D040761:Biomimetic Materials / Q000737:chemistry; D002384:Catalysis; D006865:Hydrogenation; D053768:Metal Nanoparticles / Q000737:chemistry*; D056004:Molecular Dynamics Simulation; D036103:Nanotechnology / Q000379:methods*; D009842:Oligopeptides / Q000737:chemistry*; D010165:Palladium / Q000737:chemistry*; D011487:Protein Conformation; D013499:Surface Properties
chemical_list: D000475:Alkenes; D009842:Oligopeptides; D010165:Palladium
keywords: atomic pair distribution function; biotemplating; catalysis; molecular dynamics simulations; peptides