Showing papers by "Kouji Inagaki published in 2014"
TL;DR: It is concluded that CO2 does not dissociate on "ideal" flat, stepped, or kinked Cu surfaces at low temperature to other factors such as effects of Cu adatoms, gas phase or condensed CO2 molecules, or interaction with other gas phase molecules.
Abstract: We studied the dissociative adsorption of CO2 to CO + O on the Cu(111), Cu(221), Cu(211), and Cu(11 5 9) surfaces by using state-of-the-art density functional theory (DFT) within a generalized gradient approximation (GGA) and van der Waals density functional (vdW-DF) calculations. The activation energy for CO2 dissociation on the flat Cu(111) surface is 1.33 eV. The activation energies on stepped and kinked surfaces are 1.06 eV, 0.67 eV, and 1.02 eV for the Cu(221), Cu(211), and Cu(11 5 9) surfaces, respectively. Even though the activation energy is 0.66 eV lower on the stepped Cu(211) surface than on the flat Cu(111) surface, we conclude that CO2 does not dissociate on “ideal” flat, stepped, or kinked Cu surfaces at low temperature. We attribute the discrepancy between our theoretical results and experimentally observed CO2 dissociation on stepped Cu surfaces below 150 K to other factors such as effects of Cu adatoms, gas phase or condensed CO2 molecules, or interaction with other gas phase molecules.
61 citations
TL;DR: In this paper, a catalyst-referred etching (CARE) method is proposed to produce a crystallographically undamaged and smooth SiC surface, where Pt is used as a catalyst and HF solution is employed as an etchant.
Abstract: We have developed a novel abrasive-free planarization method, which we term catalyst-referred etching (CARE). In silicon carbide (SiC) CARE, Pt is used as a catalyst and HF solution is used as an etchant. CARE produces a crystallographically undamaged and smooth SiC surface. To understand the removal mechanism at the topmost surface of SiC in the CARE process, we performed first-principles reaction path simulations using the simulation tool for atom technology (STATE) program package. These calculations are based on the density functional theory within the generalized gradient approximation of Perdew et al. The barrier height of the dissociative adsorption of HF on a SiC surface was evaluated by the climbing image nudged elastic band method. We present simulation results for the initial stages of the etching process. The reaction barrier height for adsorption of the first HF is 1.2 eV.
1 citations