Cs-RHO Goes from Worst to Best as Water Enhances Equilibrium CO Adsorption via Phase Change.

The strong affinity of water to zeolite adsorbents has made adsorption of CO from humid gas mixtures such as flue gas nearly impossible under equilibrated conditions. Here, in this manuscript, we describe a unique cooperative adsorption mechanism between HO and Cs cations on Cs-RHO zeolite, which actually facilitates the equilibrium adsorption of CO under humid conditions. Our data demonstrate that, at a relative humidity of 5%, Cs-RHO adsorbs 3-fold higher amounts of CO relative to dry conditions, at a temperature of 30 °C and CO pressure of 1 bar.

Synthesis of Highly Active Pd@Cu-Pt/C Methanol Oxidation Electrocatalysts via Continuous, Co-Electroless Deposition.

Controlled deposition of metals is essential for the creation of bimetallic catalysts having predictable composition and character. Continuous co-electroless deposition (co-ED) permits the creation of bimetallic catalysts with predictive control over composition. This method was applied to create a suite of Cu-Pt mixed-metal shell catalysts for use in methanol electrooxidation in direct methanol fuel cell applications (DMFCs).

Fabrication of biodegradable particles with tunable morphologies by the addition of resveratrol to oil in water emulsions.

Particles for biomedical applications can be produced by emulsifying biocompatible polymers dissolved in an organic solvent in water. The emulsion is then transferred to an extraction bath that removes the solvent from the dispersed droplets, which leads to polymer precipitation and particle formation. Typically, the particles are smooth and spherical, likely because the droplets remain fluid throughout the solvent extraction process allowing minimization of surface area as the volume decreases.

Selective Catalytic Chemistry at Rhodium(II) Nodes in Bimetallic Metal-Organic Frameworks.

We report the first study of a gas-phase reaction catalyzed by highly dispersed sites at the metal nodes of a crystalline metal-organic framework (MOF). Specifically, CuRhBTC (BTC =benzenetricarboxylate) exhibited hydrogenation activity, while other isostructural monometallic and bimetallic MOFs did not. Our multi-technique characterization identifies the oxidation state of Rh in CuRhBTC as +2, which is a Rh oxidation state that has not previously been observed for crystalline MOF metal nodes.

Platinum-ruthenium bimetallic clusters on graphite: a comparison of vapor deposition and electroless deposition methods.

Bimetallic Pt-Ru clusters have been grown on highly ordered pyrolytic graphite (HOPG) surfaces by vapor deposition and by electroless deposition. These studies help to bridge the material gap between well-characterized vapor deposited clusters and electrolessly deposited clusters, which are better suited for industrial catalyst preparation. In the vapor deposition experiments, bimetallic clusters were formed by the sequential deposition of Pt on Ru or Ru on Pt.

Novel recirculating loop reactor for studies on model catalysts: CO oxidation on Pt/TiO2(110).

A novel recirculating loop microreactor coupled to an ultrahigh vacuum (UHV) chamber has been constructed for the kinetic evaluation of model catalysts, which can be fully characterized by UHV surface science techniques. The challenge for this reactor design is to attain sufficient sensitivity to detect reactions on model single-crystal surfaces, which have a low number of active sites compared to conventional catalysts of equivalent mass. To this end, the total dead volume of the reactor system is minimized (32 cm(3)), and the system is operated in recirculation mode so that product concentrations build up to detectable levels over time.

Preparation and structural analysis of carbon-supported Co core/Pt shell electrocatalysts using electroless deposition methods.

Cobalt core/platinum shell nanoparticles were prepared by the electroless deposition (ED) of Pt on carbon-supported cobalt catalyst (Co/C) and verified by HRTEM images. For a 2.0 wt % Co/C core, the ED technique permitted the Pt loading to be adjusted to obtain a series of bimetallic compositions with varying numbers of monolayers (ML).