Boosting the catalysis of gold by O2 activation at Au-SiO2 interface

Yunlai Zhang,Botao Qiao,Masatake Haruta,Lin Li,Bingsen Zhang,Yiming Niu,Junying Zhang,Bing Han,Rui Si,Keju Sun,Li Sun,Jiahui Huang,Feng Hong

doi:10.1038/s41467-019-14241-8

Abstract

Supported gold (Au) nanocatalysts have attracted extensive interests in the past decades because of their unique catalytic properties for a number of key chemical reactions, especially in (selective) oxidations. The activation of O2 on Au nanocatalysts is crucial and remains a challenge because only small Au nanoparticles (NPs) can effectively activate O2. This severely limits their practical application because Au NPs inevitably sinter into larger ones during reaction due to their low Taman temperature. Here we construct a Au-SiO2 interface by depositing thin SiO2 layer onto Au/TiO2 and calcination at high temperatures and demonstrate that the interface can be not only highly sintering resistant but also extremely active for O2 activation. This work provides insights into the catalysis of Au nanocatalysts and paves a way for the design and development of highly active supported Au catalysts with excellent thermal stability.

Highlights

Supported gold (Au) nanocatalysts have attracted extensive interests in the past decades because of their unique catalytic properties for a number of key chemical reactions, especially in oxidations
Supported Au nanocatalysts have much higher activity in water-gas shift (WGS) reaction than other catalyst formulas including the commercial catalysts in use[17,18]
SiO2 modification of Au/TiO2 was performed by one pot co-deposition-precipitation of Au and Si precursors on TiO2 support and calcined at 300 and 800 °C, denoted as Au@SiO2/Ti-300 and Au@SiO2/Ti-800 (Au@SiO2/Ti–T), respectively (Supplementary Fig. 1b)

Summary

Introduction

Supported gold (Au) nanocatalysts have attracted extensive interests in the past decades because of their unique catalytic properties for a number of key chemical reactions, especially in (selective) oxidations. The HRTEM and XRD characterization results demonstrated clearly the role of coating SiO2 layer in preventing the sintering of Au NPs upon high-temperature calcination.

Results

Conclusion