Pure Nanoporous Gold Powder: Synthesis and Catalytic Properties

Abstract

MATERIAUX:SURFACES+TDR:FMO:LMA:JROInternational audienc

Ozone-Activated Nanoporous Gold: A Stable and Storable Material for Catalytic Oxidation

“…[9][10][11] Recently, nanoporous metal materials have been prepared using a wide variety of methods, including dealloying of bulk alloys as well as bottomup synthetic approaches. [12][13][14][15][16][17][18][19][20][21][22][23] In particular, free-standing nanoporous Au (npAu) etched from bulk Ag-Au alloys via a method that results in a dilute Ag-Au alloy (~1-3% Ag) has been investigated as a catalyst for oxidative processes, including the selective partial oxidation of alcohols. 5,7,19,20 Nanoporous Au sustains activity over a relatively extended period, 19,20 most likely due to the nanoporous morphology which does not readily agglomerate at moderate temperatures.…”

“…The residual Ag dissociates molecular oxygen (O 2 ) to form adsorbed O, and the amount of Ag regulates the oxidative strength of the material. 5,18,20,24,25 Two major challenges for the use of these nanoporous materials for catalysis are (1) activating them readily and (2) sustaining their activity. The current method for activating npAu materials for catalytic partial oxidation involves flowing a mixture of reactant gases, such as CO and O 2 , over the catalyst at approximately 75 °C until the material becomes active for CO oxidation.…”

Influence of the partner oxide on the catalytic properties of Au/Ce x Zr 1 − x highly loaded gold catalysts

“…. ., is much less pronounced for nanoporous systems than on nanoparticles [30]. In the present case this phenomenon is clearly observed on Au/ZrO 2 but surprisingly, the samples containing ceria present an opposite effect: when H 2 is introduced in the reactive mixture, the CO conversion rate is drastically decreased.…”

“…Method for producing the different catalysts studied herein is already described elsewhere [29][30][31]. Here, this two steps method has been also applied to ternary (Au-CeZr) intermetallics in order to synthesize an intimate mixture of a skeletal gold structure with nanostructured oxide (ZrO 2 , CeO 2 ).…”

Selective-leaching method to fabricate an Ir surface-enriched Ir-Ni oxide electrocatalyst for water oxidation

“…The rearrangement of the remaining noble metal atoms in the course of leaching may also result in noble metal surface-enriched porous and/or core-shell structures. This leaching process had been extensively used in making nanoporous gold [35] and core-shell structure of noble metals such as Pt-Cu, Pt-Co, and Pt-Ni for ORR electrocatalysis [35][36][37][38], but seldom explored in making porous metal electrocatlysts for OER.…”