The optical technique of reflection anisotropy spectroscopy ͑RAS͒ has been used to study the Cu(110)-(1ϫ2) surface reconstruction induced by Na adsorption. Room temperature deposition of submonolayer coverages of Na onto the Cu͑110͒ surface results in the (1ϫ2) reconstruction and is known to induce energy shifts in both the occupied and unoccupied surface states at the Ȳ point on Cu͑110͒. Transitions between these surface states have been associated with a peak observed at 2.1 eV in the RA spectrum. We report RAS studies of the reconstruction and relate changes in the RA spectra at 2.1 eV to changes in the surface states induced by Na adsorption.

Catalytic combustion of hydrocarbons is an important technology to produce energy. Compared to conventional flame combustion, the catalyst enables this process to operate at lower temperatures; hence, reducing the energy required for efficient combustion. The reaction and activation energies of direct combustion of hydrocarbons (CH → C + H) on a series of metal surfaces were investigated using density functional theory (DFT). The data obtained for the Ag, Au, Al, Cu, Rh, Pt, and Pd surfaces were used to investigate the validity of the Brønsted-Evans-Polanyi (BEP) and transition state scaling (TSS) relations for this reaction on these surfaces. These relations were found to be valid (R2 = 0.94 for the BEP correlation and R2 = 1.0 for the TSS correlation) and were therefore used to estimate the energetics of the combustion reaction on Ni, Co, and Fe surfaces. It was found that the estimated transition state and activation energies (ETS = −69.70 eV and Ea = 1.20 eV for Ni, ETS = −87.93 eV and Ea = 1.08 eV for Co and ETS = −92.45 eV and Ea = 0.83 eV for Fe) are in agreement with those obtained by DFT calculations (ETS = −69.98 eV and Ea = 1.23 eV for Ni, ETS = −87.88 eV and Ea = 1.08 eV for Co and ETS = −92.57 eV and Ea = 0.79 eV for Fe). Therefore, these relations can be used to predict energetics of this reaction on these surfaces without doing the time consuming transition state calculations. Also, the calculations show that the activation barrier for CH dissociation decreases in the order Ag ˃ Au ˃ Al ˃ Cu ˃ Pt ˃ Pd ˃ Ni > Co > Rh > Fe.Electronic supplementary materialThe online version of this article (10.1007/s00894-018-3585-z) contains supplementary material, which is available to authorized users.

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