Update on selective oxidation using gold

Abstract

This critical review aims to update the recent development in the selective oxidation of organic compounds by gold catalysis, highlighting the progress in the last three years. Following the impressive developments in the last decades, several protocols for catalytic oxidation are today available, which are based on the extraordinary properties of gold in terms of catalytic activity, selectivity, reusability and resistance to poisons. Beside many other applications, gold can be recommended for green processes dedicated to fine chemicals, pharmaceuticals and the food industry owing to its recognized bio-compatibility. The collected literature is focused on experiments concerning the oxidation of different chemical groups and could be of interest, in the wide area of organic chemistry, for improving previous processes or for exploring new catalytic pathways (174 references).

Direct visualization of quasi-ordered oxygen chain structures on Au(110)-(1 × 2)

“…1b, 2d), in agreement with previous work. [30] This structure is consistent with the length of (2+n)a of features along the [1][2][3][4][5][6][7][8][9][10] direction, as determined by STM. Within this structure model, features with n>2 darker gold atoms contain (n-2) atoms that are perturbed by two oxygen atoms.…”

“…[1] Prof. Madix, who is being honored by this special issue, was a pioneer in the application of scanning tunneling microscopy (STM) to the investigation of chemical reactions on surfaces, including coinage metals. [2] Because gold is an efficient and selective catalyst for oxidation processes [3][4][5][6][7][8][9] there is considerable interest in imaging reactant species, including adsorbed oxygen (O ads ), on its surfaces. Model studies on single crystal surfaces [10][11][12][13] provide a mechanistic understanding of how oxidative processes are promoted on Au, [14] with the final goal of predicting new reactions.…”

“…[19] Herein, we investigate the bonding of O on Au(110) in order to better exploit atomic-scale imaging using STM in conjunction with DFT studies. The Au(110) surface reconstructs to the missing-row Au(110)-(1x2) structure, which consists of an ordered array of (111) microfacets [20][21][22] capped by rows of atoms with low coordination number along the [1][2][3][4][5][6][7][8][9][10] direction (Fig. 1a).…”

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

“…After the pioneering works of Hutchings [1] and Haruta et al [2], the high activity of gold catalysts has demonstrated that gold can be the catalyst of choice for an important number of chemical reactions such as selective oxidations and hydrogenations of organic substrates [2][3][4][5][6], water-gas shift reaction [7][8][9], acetylene hydrochlorination [10,11], direct synthesis of hydrogen peroxide [12], reduction of NO to N 2 [13,14] and the addition of nucleophiles to acetylenes [15], among others [16,17]. Although gold has been sometimes alloyed with other metals such as Pd, Cu and Ag, in most cases, gold alone exhibits high and exceptional catalytic activity.…”

Catalysis using colloidal-supported gold-based nanoparticles

“…From these studies, it was identified that when Au is present as very small particles, with a mean diameter below 10 nm, it becomes surprisingly catalytically active, especially at low temperatures. After these important discoveries, many research groups in academia and industry have focused their research upon exploring the catalytic performance of Au catalysts for a wide range of oxidation and hydrogenation reactions [5,6]. New discoveries have been reported since that period, and novel, designed supported gold nanoparticles have shown to be extremely effective catalysts for the oxidation of CO [7][8][9][10][11], the selective oxidation of alcohols and polyols [12,13], the epoxidation of olefins [14,15], the hydrochlorination of ethyne [16], the selective hydrogenation of unsaturated carbonyl and nitro groups [17], and the direct synthesis of hydrogen peroxide from molecular hydrogen and oxygen [18].…”