Deposition of Gold Particles on Mesoporous Catalyst Supports by Sonochemical Method, and their Catalytic Performance for CO Oxidation

Abstract

Supported gold catalysts on the mesoporous (MSP) metal oxides were prepared by a one-step, ultrasound-assisted reduction method, and characterized by XRD, HRTEM, EDX, BET, and XPS analysis. Their catalytic activities were examined in the oxidation of CO. Compared to the Au/Fe 2 O 3 (MSP) catalyst, the Au/ TiO 2 (MSP) and Au/Fe 2 O 3 -TiO 2 (MSP) catalysts exhibited higher catalytic activity in the oxidation of CO at low temperatures. The high catalytic activity of Au/TiO 2 (MSP) was attributed to the metallic state of the gold nanoparticles, their small size (2-2.5 nm), and their high dispersion on the catalyst support.

Sustainable Preparation of Supported Metal Nanoparticles and Their Applications in Catalysis

“…CeO 2 ) metal oxides. Among the metal oxides, silica, [32][33][34][35] alumina, [32,34,[36][37][38] , titania, [34,35,[39][40][41][42] ceria [32,34,36,43] and zirconia [36,37,44] are the most commonly employed supports. Superparamagnetic oxides (e.g.…”

“…[59] Deposition and reduction of the particles (favoured by ultrasonic radiation) takes place almost consecutively so that the heating step normally employed in other protocols can be avoided, [39] making the preparation of supported metal nanoparticles more energy-efficient and environmentally friendly. Another interesting feature of the methodology is the controllable nanoparticle size distribution that can be achieved.…”

“…[46] Reproduced with permission. www.chemsuschem.org use of a reductant including sodium borohydride, [62] hydrogen [39] and hydrogen/polyalcohols, [60][61][62][63] to further ensure the reduction of the nanoparticle on the support.…”

Designer Nanomaterials for the Production of Energy and High Value‐Added Chemicals

“…Ultrasounds (USs) remarkably enhance mass transport, reducing the diffusion layer thickness and also affect the surface morphology of the treated materials, normally enhancing the surface contact area [22]. Deposition and reduction of the particles (favored by ultrasonic radiation) takes place almost consecutively, so that the heating step normally employed in other protocols can be avoided [23]. These advantages are related to the acoustic cavitation phenomena, that is, the formation, growth, and collapse of the generated bubbles in a liquid medium.…”

“…The SMNPs preparation is usually performed using a conventional ultrasonic cleaning bath or a high power probe. Although, a more controllable NPs size distribution can be achieved with this methodology, these ultrasonic-assisted protocols sometimes require the additional use of a reductant including sodium borohydride [24], hydrogen [23], and hydrogen + polyalcohols [25], to further ensure the reduction of NPs on the supports.…”