Activation and deactivation of Au-Cu/SBA-15 catalyst for preferential oxidation of CO in H ₂-Rich Gas

TY - JOUR

T1 - Activation and deactivation of Au-Cu/SBA-15 catalyst for preferential oxidation of CO in H 2-Rich Gas

AU - Li, Xu

AU - Fang, Stella See Soon

AU - Teo, Jaclyn

AU - Foo, Yong Lim

AU - Borgna, Armando

AU - Lin, Ming

AU - Zhong, Ziyi

PY - 2012/3/2

Y1 - 2012/3/2

N2 - This work aims to develop an efficient catalyst for preferential oxidation (PROX) of CO in a H 2-rich gas and obtain a clear structure-property relationship of the catalyst. A Au/CuO/SBA-15 catalyst was designed and prepared via a nanoengineering approach in which the metallic particles of average size 3 nm located in the vicinity of CuO particles were highly dispersed on the SBA-15 support. It was found that the CuO particles could reduce the gold (Au) particle size, stabilize the Au particles, and facilitate the activation of molecular oxygen. Although this catalyst is extremely active for the PROX reaction at room temperature and superior to the Au/SBA-15 and CuO/SBA-15 catalysts, it deactivates easily. Clear experimental evidence showed that CuO was reduced to Cu 2O and Cu in the reductive reaction gas mixture, and the Cu further combined/dissolved into the Au particles during the reaction. The alloying of Au and Cu not only decreased the catalytic activity of the Au particles but also reduced the ability of CuO to activate molecular oxygen. Fortunately, this alloying process could be reversed via a simple calcination in air to activate the catalyst. The identification of the catalyst structural evolution and this new contributing factor toward the deactivation of the Au catalysts has provided insights into the field of Au catalysis.

AB - This work aims to develop an efficient catalyst for preferential oxidation (PROX) of CO in a H 2-rich gas and obtain a clear structure-property relationship of the catalyst. A Au/CuO/SBA-15 catalyst was designed and prepared via a nanoengineering approach in which the metallic particles of average size 3 nm located in the vicinity of CuO particles were highly dispersed on the SBA-15 support. It was found that the CuO particles could reduce the gold (Au) particle size, stabilize the Au particles, and facilitate the activation of molecular oxygen. Although this catalyst is extremely active for the PROX reaction at room temperature and superior to the Au/SBA-15 and CuO/SBA-15 catalysts, it deactivates easily. Clear experimental evidence showed that CuO was reduced to Cu 2O and Cu in the reductive reaction gas mixture, and the Cu further combined/dissolved into the Au particles during the reaction. The alloying of Au and Cu not only decreased the catalytic activity of the Au particles but also reduced the ability of CuO to activate molecular oxygen. Fortunately, this alloying process could be reversed via a simple calcination in air to activate the catalyst. The identification of the catalyst structural evolution and this new contributing factor toward the deactivation of the Au catalysts has provided insights into the field of Au catalysis.

KW - AuCu alloy

KW - PROX reaction

KW - activation

KW - deactivation

KW - gold catalyst

KW - particle size

KW - point EDX analysis

UR - http://www.scopus.com/inward/record.url?scp=84863277904&partnerID=8YFLogxK

U2 - 10.1021/cs200536a

DO - 10.1021/cs200536a

M3 - 文章

AN - SCOPUS:84863277904

SN - 2155-5435

VL - 2

SP - 360

EP - 369

JO - ACS Catalysis

JF - ACS Catalysis

IS - 3

ER -