Development of novel supported gold catalysts: A materials perspective

Abstract

Since Haruta et al. discovered that small gold nanoparticles finely dispersed on certain metal oxide supports can exhibit surprisingly high activity in CO oxidation below room temperature, heterogeneous catalysis by supported gold nanoparticles has attracted tremendous attention. The majority of publications deal with the preparation and characterization of conventional gold catalysts (e.g., Au/TiO 2 ), the use of gold catalysts in various catalytic reactions, as well as elucidation of the nature of the active sites and reaction mechanisms. In this overview, we highlight the development of novel supported gold catalysts from a materials perspective. Examples, mostly from those reported by our group, are given concerning the development of simple gold catalysts with single metal-support interfaces and heterostructured gold catalysts with complicated interfacial structures. Catalysts in the first category include active Au/SiO 2 and Au/metal phosphate catalysts, and those in the second category include catalysts prepared by pre-modification of supports before loading gold, by post-modification of supported gold catalysts, or by simultaneous dispersion of gold and an inorganic component onto a support. CO oxidation has generally been employed as a probe reaction to screen the activities of these catalysts. These novel gold catalysts not only provide possibilities for applied catalysis, but also furnish grounds for fundamental research.

Enhanced Catalytic Activity of Supported Gold Catalysts for Oxidation of Noxious Environmental Pollutant CO

“…However, one problem generally encountered with these catalysts is the relatively weak metal-support interaction, which may lead to the sintering of gold nanoparticles at elevated temperatures. Therefore, several strategies have been implemented to construct gold 2 Indian Journal of Materials Science catalysts with diversified local structures and better catalytic performance [14][15][16].…”

Synthesis of Gold Catalysts Supported on Mesoporous Silica Materials: Recent Developments

“…The chloride remaining on the support promotes the aggregation of AuNPs and may poison the active sites of the catalyst [18,22,34]. Consequently, numerous papers describing different methods to incorporate AuNPs on a variety of metal oxides, including TiO 2 , Al 2 O 3 , Fe 2 O 3 , CeO 2 , Co 3 O 4 , ZrO 2 , MgO and SiO 2 have been published by different research groups to overcome this problem [18,35,36]. Depending on the metal oxide support, gold catalysts can be synthesized mainly by deposition-precipitation, co-precipitation, colloidal dispersion and gas-and liquid-phase grafting of organo-gold complexes.…”

“…Only two interesting contributions focusing on the preparation of Au/SiO 2 catalysts, mainly for CO oxidation, have been published by Ma and Dai [35] and Ma et al [36]. Herein we reviewed the main methods to synthesize gold catalysts supported on MSM, as well as some selected examples of their catalytic applications, in order to contribute to the fascinating topic of catalysis by gold.…”

“…Because of the large number of available literature and applications, neither the characterization methods of the synthesized gold catalysts nor the physical chemistry of the catalytic reactions is covered in this review. Readers interested on these topics can find useful information in this special issue of Catalysts, in the recent thematic issue of the Chemical Society Reviews (2008 Gold: Chemistry, Materials and Catalysis issue), and in the current specific literature [5,35,40,50].…”

Durable PROX catalyst based on gold nanoparticles and hydrophobic silica

“…10 Another cause of 20 deactivation is the formation of poisoning carbonate-type surface species. 11,12 Most approaches aiming at producing more stable gold catalysts 13 have focused so far on enhancing the thermal stability of gold nanoparticles against sintering 14 by increasing the so- 25 called "strength of gold-support interaction", in e.g. Au/Al 2 O 3 , 15,16 Au/metal-phosphates, 17 core-shell and yolk-shell nanocomposites, 18 Au/multi-layered oxides 19 and SiO 2 -modified Au/TiO 2 catalysts.…”