Response to Comment on "Density Functional Theory and 3D-RISM-KH molecular theory of solvation studies of CO reduction on Cu-, CuO-, Fe-, and F3O-based nanocatalysts".

In response to the Comment on "Density Functional Theory and 3D-RISM-KH molecular theory of solvation studies of CO reduction on Cu-, Cu2O-, Fe-, and FeO-based nanocatalysts" (Gusarov J Mol Model 27:344-344, 1), the behavior of a CO* molecule on a Cu nanocatalyst slab without a solution considered in the Comment is considerably different from our case of this system in 1.0 Mol KHPO ambient aqueous solution. Moreover, our calculations for CO* on Cu without a solution that we presented in our article are similar to those shown in the Comment.

Density functional theory and 3D-RISM-KH molecular theory of solvation studies of CO reduction on Cu-, CuO-, Fe-, and FeO-based nanocatalysts.

Using OpenMX quantum chemistry software for self-consistent field calculations of electronic structure with geometry optimization and 3D-RISM-KH molecular theory of solvation for 3D site distribution functions and solvation free energy, we modeled the reduction of CO+H in ambient aqueous electrolyte solution of 1.0-M KHPO into (i) formic acid HCOOH and (ii) CO HO on the surfaces of Cu-, Fe-, CuO-, and FeO-based nanocatalysts. It is applicable to its further reduction to hydrocarbons.

Molecular simulation of gas adsorption, diffusion, and permeation in hydrated Nafion membranes.

Molecular simulations were performed to characterize hydrated Nafion membranes in terms of gas adsorption, diffusion, and permeation. The experimental results validate the molecular model of Nafion with respect to material density, morphology, free volume, and water diffusivity. Nafion's adsorption property is examined in terms of the solubility and adsorption isotherms for gases, including H(2), O(2), and N(2).

Microstructure-based modeling of aging mechanisms in catalyst layers of polymer electrolyte fuel cells.

This work is comprised of a versatile multiscale modeling of carbon corrosion processes in catalyst layers (CLs) of polymer electrolyte fuel cells (PEFCs). Slow rates of electrocatalytic processes in CLs and materials aging are the main sources of voltage loss in PEFCs under realistic operating conditions. We combined microstructure data obtained from coarse-grained molecular dynamics (CGMD) simulations with a detailed description of the nanoscale elementary kinetic processes and electrochemical double-layer effects at the catalyst/electrolyte and carbon/electrolyte interfaces.

Nanostructured Pt-alloy electrocatalysts for PEM fuel cell oxygen reduction reaction.

In this critical review, we present the current technological advances in proton exchange membrane (PEM) fuel cell catalysis, with a focus on strategies for developing nanostructured Pt-alloys as electrocatalysts for the oxygen reduction reaction (ORR). The achievements are reviewed and the major challenges, including high cost, insufficient activity and low stability, are addressed and discussed. The nanostructured Pt-alloy catalysts can be grouped into different clusters: (i) Pt-alloy nanoparticles, (ii) Pt-alloy nanotextures such as Pt-skins/monolayers on top of base metals, and (iii) branched or anisotropic elongated Pt or Pt-alloy nanostructures.

Note: Determination of effective gas diffusion coefficients of stainless steel films with differently shaped holes using a Loschmidt diffusion cell.

In this work, an in-house made Loschmidt diffusion cell is used to measure the effective O(2)-N(2) diffusion coefficients through four porous samples of different simple pore structures. One-dimensional through-plane mass diffusion theory is applied to process the experimental data. It is found that both bulk diffusion coefficient and the effective gas diffusion coefficients of the samples can then be precisely determined, and the measured bulk one is in good agreement with the literature value.

Electricity generation from carbon monoxide in a single chamber microbial fuel cell.

Electricity production from carbon monoxide (CO) is demonstrated in a single chamber microbial fuel cell (MFC) with a CoTMPP-based air cathode. The MFC was inoculated with anaerobic sludge and continuously sparged with CO as a sole carbon source. Volumetric power output was maximized at a CO flow rate of 4.

Molecular dynamics simulations of adsorption and diffusion of gases in silicon-carbide nanotubes.

Silicon carbide nanotubes (SiCNTs) are new materials with excellent properties, such as high thermal stability and mechanical strength, which are much improved over those of their carboneous counterparts, namely, carbon nanotubes (CNTs). Gas separation processes at high temperatures and pressures may be improved by developing mixed-matrix membranes that contain SiCNTs. Such nanotubes are also of interest in other important processes, such as hydrogen production and its storage, as well as separation by supercritical adsorption.

Thermal-lens study of photochemical reaction kinetics.

We consider the time dependence of the absorption coefficient due to the photoinduced chemical reaction (PCR) and species diffusion to calculate the temperature rise in the thermal-lens (TL) effect. The TL signal at the detector plane is also calculated. This theoretical approach removes the restriction that the PCR time constant is much greater than the characteristic TL time constant, which was assumed in a previously published model.

The effect of relative humidity on binary gas diffusion.

The dependence of diffusion coefficient of O2-N2 mixture in the presence of water vapor was experimentally determined as a function of relative humidity (RH) with different temperatures using an in-house made Loschmidt diffusion cell. The experimental results showed that O2-N2 diffusion coefficient increased more than 17% when RH increased from 0% to 80% at 79 degrees C. In the experiments, the RH in both top and bottom chambers of the diffusion cell were the same, and the pressure inside the diffusion cell was kept as ambient pressure (1 atm.

Nanophase segregation and water dynamics in hydrated Nafion: molecular modeling and experimental validation.

Reported results of coarse-grained molecular dynamics simulations rationalize the effect of water on the phase-segregated morphology of Nafion ionomers. We analyzed density maps and radial distribution functions and correlated them with domain structures, distributions of protogenic side chains, and water transport properties. The mesoscopic structures exhibit spongelike morphologies.

Time-resolved thermal mirror technique with top-hat cw laser excitation.

A theoretical model was developed for time-resolved thermal mirror spectroscopy under top-hat cw laser excitation that induced a nanoscale surface displacement of a low absorption sample. An additional phase shift to the electrical field of a TEM(00) probe beam reflected from the surface displacement was derived, and Fresnel diffraction theory was used to calculate the propagation of the probe beam. With the theory, optical and thermal properties of three glasses were measured, and found to be consistent with literature values.

Top-hat cw-laser-induced time-resolved mode-mismatched thermal lens spectroscopy for quantitative analysis of low-absorption materials.

Thermal lens spectroscopy is a highly sensitive and versatile photothermal technique for material analysis, providing optical and thermal properties. To use less expensive multimode non-Gaussian lasers for quantitative analysis of low-absorption materials, this Letter presents a theoretical model for time-resolved mode-mismatched thermal lens spectroscopy induced by a cw laser with a top-hat profile. The temperature profile in a sample was calculated, and the intensity of the probe beam center at the detector plane was also derived using the Fresnel diffraction theory.

Probe beam size effect on the measurement of the distance between the probe beam and the sample in photothermal deflection.

A distance-scan method to determine the distance between the probe beam and sample, which is not easily measured exactly, in photothermal deflection (PD) was reported, with which the distance and thermal diffusivity of the deflecting medium can be simultaneously measured. Probe beam size effect (PBSE) on PD phase signal was quantitatively analyzed to clearly show its physical meaning. The measured distance was experimentally verified as correct and reliable, and the measured thermal diffusivities of N2 and CO2 are in good agreement with the literature values.