CO oxidation catalyzed by silver nanoclusters: mechanism and effects of charge

Abstract

The mechanism of the CO oxidation promoted by a neutral Ag(55) cluster was investigated extensively, using density functional theory calculations. The CO oxidation process catalyzed by anionic and cationic Ag(55) clusters was also studied, to clarify the effects of the charge state. The Eley-Rideal (ER) and Langmuir-Hinshelwood (LH) mechanisms were discussed in detail. Six reaction pathways were found for the Ag(55)-mediated CO oxidation. It was found that the ER mechanism competed with the LH mechanism. The rate-limiting step of the CO oxidation was the reaction of CO with the Ag(55)O species. All of the anionic, neutral, and cationic Ag(55) clusters were able to promote CO oxidation at low temperatures. The present results enrich our understanding of the catalytic oxidation of CO by nano-sized Ag-based catalysts.

Structure of Tiopronin-Protected Silver Nanoclusters in a One-Dimensional Assembly

“…1,2 The unique properties of NCs have initiated their application to many fields of science such as biological sensing, 3,4 antibacterial applications, [5][6][7] and catalysis 4,8,9 , to name a few. Several different types of these metal NCs have been synthesized using protecting ligands such as proteins, 10 peptides, 3,11 and dendrimers; 12 although the most well-researched NCs are those prepared with thiols, as they provide high stability, small cluster size, and low size distributions.…”

Facile synthesis of novel MnOx nano-structures and their catalytic performance on CO oxidation

“…More recently, nanosized metal catalysts have been found to be effective alternatives for combustion reactions at relatively low temperatures because of the large specific surface area and the ability to release the lattice oxygen to produce an oxygen vacancy. [1][2][3][4] As an important functional metal oxide, manganese oxides (MnO x ) have characteristics such as mixed valence (such as Mn 3+ and Mn 4+ ) and facile phase transformation, moreover, it still attracts considerable attention from both academia and industry due to the low cost comparing to the expensive noble metals (Au, 5 Ag, 6 Pt, 7 and Pd 8 ) and the environmental friendliness. Therefore, a number of controllable synthetic methods have been developed for the fabrication of uniform nanostructured MnO x , for example, hydrothermal method, 9,10 sol-gel method, 11 precursor route 12,13 and microwave synthesis 14,15 et al 16,17 However, most of those methods led to only one manganese oxide phase as the final product.…”

Three-dimensional TiO2/CeO2 nanowire composite for efficient formaldehyde oxidation at low temperature

“…7 Numerous efforts have been devoted to removing the indoor HCHO, and some strategies have been proposed in the recent years. [8][9][10] One of the most effective methods is to convert HCHO into CO 2 and H 2 O over catalysts via low-temperature thermal catalytic oxidation in terms of its low cost, environmentally friendly reaction conditions and energy saving. 11 To improve the efficiency and reduce the reaction temperature of the thermal catalytic HCHO oxidation, considerable attention has focused on the design and synthesis of high-performance catalysts.…”