Nanoparticulate TiO2-promoted PtRu/C catalyst for methanol oxidation: TiO2 nanoparticles promoted PtRu/C catalyst for MOR

To improve the electrocatalytic properties of PtRu/C in methanol electrooxidation, nanoparticulate TiO2-promoted PtRu/C catalysts were prepared by directly mixing TiO2 nanoparticles with PtRu/C. Using cyclic voltammetry, it was found that the addition of 10 wt% TiO2 nanoparticles can effectively improve the electrocatalytic activity and stability of the catalyst during methanol electro-oxidation. The value of the apparent activation energy (Ea) for TiO2-PtRu/C was lower than that for pure PtRu/C at a potential range from 0.45 to 0.60 V. A synergistic effect between PtRu and TiO2 nanoparticles is likely to facilitate the removal of CO-like intermediates from the surface of PtRu catalyst and reduce the poisoning of the PtRu catalysts during methanol electrooxidation. Therefore, we conclude that the direct introduction of TiO2 nanoparticles into PtRu/ C catalysts offers an improved facile method to enhance the electrocatalytic performance of PtRu/C catalyst in methanol electrooxidation.Web of Scienc

Co-deposition of Pt and Ceria Anode Catalyst in Supercritical Carbon Dioxide for Direct Methanol Fuel Cell Applications

Pt and mixed Pt-ceria catalysts were deposited onto gas diffusion layers using supercritical fluid deposition (SFD) to fabricate thin layer electrodes for direct methanol fuel cells. Dimethyl (1,5-cyclooctadiene) platinum (II) (CODPtMe2) and tetrakis (2,2,6,6-tetramethyl 3,5-heptanedionato) cerium (IV) (Ce(tmhd)(4)) were used as precursors. Hydrogen-assisted Pt deposition was performed in compressed carbon dioxide at 60 degrees C and 17.2 MPa to yield high purity Pt on carbon-black based gas diffusion layers. During the preparation of the mixed Pt-ceria catalyst, hydrogen reduction of CODPtMe2 to yield Pt catalyzed the deposition of ceria from Ce(tmhd)(4) enabling co-deposition at 150 degrees C. The catalyst layers were characterized using Xray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscope-energy dispersive spectral (SEM-EDS) analyses. Their electrochemical performance toward methanol oxidation was examined in half cell mode using a three electrode assembly as well as in fuel cell mode. The thin layer electrodes formed via SFD exhibited higher performance in fuel cell operations compared to those prepared by the conventional brush-paint method. Furthermore, the Pt-ceria catalyst with an optimized composition exhibited greater methanol oxidation activity than pure platinum. (C) 2012 Elsevier Ltd. All rights reserved

Recent Developments in the Modelling of Heterogeneous Catalysts for CO2 Conversion to Chemicals

"This is the peer reviewed version of the following article: Recent Developments in the Modelling of Heterogeneous Catalysts for CO2 Conversion to Chemicals, which has been published in final form at https://doi.org/10.1002/cctc.201901879. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.Density functional theory (DFT) of the CO2 behavior on the catalyst surface provides valuable insights about the C=O bond activation, information about adsorption and dissociation of CO2, understanding the elementary steps involved in the mechanism of the CO2 hydrogenation reaction. Nowadays, DFT computational studies for the catalytic hydrogenation of CO2 are becoming very popular. Therefore, this article is focused on a comprehensive review of the DFT studies in thermocatalytic hydrogenation of CO2 at the gas‐surface interface and discusses three aspects: 1) processes taking place on the surfaces and facets of transition metal heterogeneous catalysts, 2) adsorption of CO2 on surfaces of different transition metals; 3) current understanding of reaction mechanisms taking place on the catalytic surface for the production of different compounds. A detailed schematic overview of the possible CO2 hydrogenation mechanisms and DFT simulations presented here will enhance the current understanding of the CO2 catalytic hydrogenation