title: Atomic layer deposition overcoating: tuning catalyst selectivity for biomass conversion.
abstract: The terraces, edges, and facets of nanoparticles are all active sites for heterogeneous catalysis. These different active sites may cause the formation of various products during the catalytic reaction. Here we report that the step sites of Pd nanoparticles (NPs) can be covered precisely by the atomic layer deposition (ALD) method, whereas the terrace sites remain as active component for the hydrogenation of furfural. Increasing the thickness of the ALD-generated overcoats restricts the adsorption of furfural onto the step sites of Pd NPs and increases the selectivity to furan. Furan selectivities and furfural conversions are linearly correlated for samples with or without an overcoating, though the slopes differ. The ALD technique can tune the selectivity of furfural hydrogenation over Pd NPs and has improved our understanding of the reaction mechanism. The above conclusions are further supported by density functional theory (DFT) calculations.
authors.affiliation: Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, IL 60439 (USA) http://www.iact.anl.gov.
authors.forename: Hongbo
authors.initials: H
authors.lastname: Zhang
authors.forename: Xiang-Kui
authors.initials: XK
authors.lastname: Gu
authors.forename: Christian
authors.initials: C
authors.lastname: Canlas
authors.forename: A Jeremy
authors.initials: AJ
authors.lastname: Kropf
authors.forename: Payoli
authors.initials: P
authors.lastname: Aich
authors.forename: Jeffrey P
authors.initials: JP
authors.lastname: Greeley
authors.forename: Jeffrey W
authors.initials: JW
authors.lastname: Elam
authors.forename: Randall J
authors.initials: RJ
authors.lastname: Meyers
authors.forename: James A
authors.initials: JA
authors.lastname: Dumesic
authors.forename: Peter C
authors.initials: PC
authors.lastname: Stair
authors.forename: Christopher L
authors.initials: CL
authors.lastname: Marshall
mesh_terms: D018533:Biomass; D002384:Catalysis
keywords: atomic layer deposition; biomass; catalyst selectivity; hydrogenation; palladium