Title: Au20Pd1@SiO2 nanoreactors highly effective in CO oxidation

Authors: Brenda Acosta; Viridiana Evangelista; Serguei Miridonov; Sergio Fuentes; Elena Smolentseva; Andrey Simakov

Addresses: Posgrado en Física de Materiales, Centro de Investigación Científica y de Educación Superior de Ensenada, Carretera Ensenada-Tijuana 3918, Zona Playitas, C.P. 22860, Ensenada, Baja California, Mexico ' Posgrado en Física de Materiales, Centro de Investigación Científica y de Educación Superior de Ensenada, Carretera Ensenada-Tijuana 3918, Zona Playitas, C.P. 22860, Ensenada, Baja California, Mexico ' Departamento de Óptica, Centro de Investigación Científica y de Educación Superior de Ensenada, Carretera Ensenada-Tijuana 3918, Zona Playitas, C.P. 22860, Ensenada, Baja California, Mexico ' Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Km. 107 Carretera Tijuana a Ensenada, C.P. 22860, Ensenada, Baja California, Mexico ' Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Km. 107 Carretera Tijuana a Ensenada, C.P. 22860, Ensenada, Baja California, Mexico ' Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Km. 107 Carretera Tijuana a Ensenada, C.P. 22860, Ensenada, Baja California, Mexico

Abstract: Au cores partially covered with Pd (molar ratio Au20:Pd1) were homogeneously encapsulated into silica shells to form AuPd@SiO2 nanoreactors via usage of high polyvinylpyrrolidone (PVP) concentration and prolonged time of nanoparticle treatment with PVP before bimetallic nanoparticle encapsulation. The presence of both metals in the core of the nanoreactors was confirmed by means of STEM-EDS, UV-Vis and XPS. The AuPd@SiO2 nanoreactors showed enhanced catalytic activity in CO oxidation compared with that for reference Au@SiO2 nanoreactors. The developed experimental procedure for successful encapsulation of bimetallic nanoparticles into silica is relevant for the design of gold-based nanoreactors with modified cores.

Keywords: gold; palladium; nanoreactors; homogeneous encapsulation; SiO2 shell; silicon dioxide; silica; polyvinylpyrrolidone; PVP; CO oxidation; carbon monoxide; bimetallic nanoparticles; nanotechnology; catalytic activity; nanoreactor cores.

DOI: 10.1504/IJNT.2016.074532

International Journal of Nanotechnology, 2016 Vol.13 No.1/2/3, pp.168 - 184

Available online: 04 Feb 2016 *

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