Simulating periodic trends in the structure and catalytic activity of coinage metal nanoribbons

Abstract

We present a systematic density functional theory (DFT) study of the structure and catalytic activity of group 10 (Ni, Pd, Pt) and group 11 (Cu, Ag, Au) coinage metal nanoribbons. These infinite, periodic, quasi‐one‐dimensional structures are conceptually important as intermediates between small metal clusters and close‐packed metal surfaces, and have been shown experimentally to be practical catalysts. We find that nanoribbons have significantly higher predicted H2 dissociation activity than close‐packed metal surfaces consistent with their lower coordination numbers. Computed periodic trends are reasonable, with late transition states and low barriers for H2 dissociation over late group 10 nanoribbons, suggesting their promise as practical catalysts. These trends are consistent with the isolated nanoribbons' computed molecular electrostatic potentials. Calculations also predict nearly linear Brønsted–Evans–Polanyi relationships between the nanoribbons' H2 dissociation energies and dissociation barriers. We also test new meta‐generalized gradient approximation (GGA) and hybrid DFT approximations for H2 dissociation over these nanoribbons. These new functionals increase the (generally underestimated) dissociation barriers predicted by standard GGAs, motivating their continued application in surface chemistry. © 2015 Wiley Periodicals, Inc.

Revisiting alternative pathways in the Fischer–Tropsch process: Accurate density functional theory calculations on “magic” Ru12 clusters

“…The M06L meta‐GGA generally gives results intermediate between the GGAs and unrestricted B3LYP, although transition state ETS2 is somewhat lower than the other functionals. This is consistent with our previous studies of M06L for surface chemistry . The PW91 and PBE GGAs predict nearly identical results.…”

“…This is consistent with our previous studies of M06L for surface chemistry. [76,77] The PW91 and PBE GGAs predict nearly identical results.…”

Dissociation reactions of hydrogen molecules at active sites on gold clusters: A DFT study

“…[2] For example, the H 2 -D 2 exchange reaction has an activation barrier of about $8.6 kcal/mol on GNPs with a diameter less than 10 nm, which is much smaller than that of H 2 dissociation on Au(111) surface, indicating that the exchange rate constant increases with the decrease of particles size. [3][4][5] Density functional theory (DFT) calculations have been used to investigate adsorption, [6][7][8] dissociation, [9][10][11][12][13][14][15][16][17] and photochemical reactions [18][19][20][21][22] of H 2 on gold nanoparticles. For the H 2 dissociation, Takagi and co-workers adopted a Au(111) slab model and obtained about 1.55 eV (35.52 kcal/mol) activation energy.…”

“…[17,[19][20][21]37] The dissociation path of H 2 on neutral and cationic Au clusters at excited states with excitation energy of about 1.60 and 2.50 eV was reported, and activation energies of 2.18 and 2.00 eV were predicted, respectively. [18,20] The pioneering DFT study of H 2 dissociation on embedded cluster Au 12 suggests that hot electrons generated from the SPR relax to the antibonding orbital of adsorbed H 2 and promote H 2 dissociation, [25,35] while the activation barrier of 1.70-1.95 eV is very high. [3] Furthermore, Boccuzzi et al confirmed that water molecules affect the H 2 dissociation on gold-deposited TiO 2 .…”

“…Density functional theory (DFT) calculations have been used to investigate adsorption, [ 6–8 ] dissociation, [ 9–17 ] and photochemical reactions [ 18–22 ] of H 2 on gold nanoparticles. For the H 2 dissociation, Takagi and co‐workers adopted a Au(111) slab model and obtained about 1.55 eV (35.52 kcal/mol) activation energy.…”