二氧化钛修饰的二氧化硅负载金纳米颗粒：形成、形态及一氧化碳氧化活性

Silica-supported Au nanoparticles decorated by TiO2: formation, morphology, and CO oxidation activity.

作者信息

Horváth Anita, Beck Andrea, Sárkány Antal, Stefler Györgyi, Varga Zsolt, Geszti Olga, Tóth Lajos, Guczi László

机构信息

Department of Surface Chemistry and Catalysis and Radiation Safety Department, Institute of Isotopes, Hungarian Academy of Sciences, Post Office Box 77, H-1525 Budapest, Hungary.

出版信息

J Phys Chem B. 2006 Aug 10;110(31):15417-25. doi: 10.1021/jp060977b.

DOI:10.1021/jp060977b

PMID:16884263

Abstract

Au-TiO(2) interface on silica support was aimed to be produced in a controlled way by use of Au hydrosol. In method A, the Au colloids were modified by hydrolysis of the water-soluble Ti(IV) bis(ammoniumlactato)dihydroxide (TALH) precursor and then adsorbed on Aerosil SiO(2) surface. In method B, Au sol was first deposited onto the SiO(2) surface and then TALH was adsorbed on it. Regular and high-resolution transmission electron microscopy (TEM and HRTEM) and energy dispersive spectrometry (EDS) analysis allowed us to conclude that, in method A, gold particles were able to retain the precursor of TiO(2) at 1.5 wt % TiO(2) loading, but at 4 wt % TiO(2) content the promoter oxide appeared over the silica surface as well. With method B, titania was detected on silica at each TiO(2) concentration. In Au-TiO(2)/SiO(2) samples, the stability of Au particles against sintering was much higher than in Au/TiO(2). The formation of an active Au-TiO(2) perimeter was proven by the greatly increased CO oxidation activity compared to that of the reference Au/SiO(2).

摘要

旨在通过使用金溶胶以可控方式在二氧化硅载体上制备金 - 二氧化钛界面。在方法A中，通过水溶性钛（IV）双（乳酸铵）二氢氧化物（TALH）前驱体的水解对金胶体进行改性，然后吸附在气相二氧化硅SiO₂表面。在方法B中，首先将金溶胶沉积到SiO₂表面，然后将TALH吸附在其上。常规和高分辨率透射电子显微镜（TEM和HRTEM）以及能量色散光谱（EDS）分析使我们能够得出结论，在方法A中，当二氧化钛负载量为1.5 wt％时，金颗粒能够保留二氧化钛前驱体，但当二氧化钛含量为4 wt％时，促进剂氧化物也出现在二氧化硅表面。采用方法B时，在每个二氧化钛浓度下都能在二氧化硅上检测到二氧化钛。在金 - 二氧化钛/二氧化硅样品中，金颗粒抗烧结的稳定性远高于金/二氧化钛。与参考金/二氧化硅相比，一氧化碳氧化活性大大提高，证明了活性金 - 二氧化钛周边的形成。