Gold nanocatalyst is a potential catalyst for CO preferential oxidation (PROX) reaction. However, with the increase of reaction temperatures, CO conversion and CO₂ selectivity in PROX reaction will decrease due to the enhanced competition oxidation of hydrogen, which leads to a narrow temperature window.

It's still a challenge to completely remove CO at a wide temperature window and meanwhile maintain superior stability in CO-PROX reaction.

Recently, Prof. LI Can's group and Prof. HUANG Jiahui's group from theDalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences (CAS) developed a photoexcited deposition of metal oxide (PDMO) method to improve the performance of the CO-PROX reaction.

This study was published in Chem Catalysis on May 17.

Structure characterization and catalytic performance of prepared catalysts (Image by HONG Feng and WANG Shengyang)  

The researchers developed a unique and visualized strategy to selectively modify the interfacial region of Au/TiO₂ catalyst by a PDMO method based on the photocatalytic reactions induced by the surface plasmon resonance (SPR) of gold NPs. Au/TiO₂ catalyst is a well-known gold nanocatalyst and also a representative plasmonic photocatalyst.

They modified the interface of Au/TiO₂ catalyst, and eliminated CO in a very wide temperature range, which exhibited superior performance in CO-PROX reaction. Meanwhile, the decorated PbO₂ also improved the long-term stability of Au/TiO₂ even in a harsh condition.

"This study is promising for gold catalysts to remove the trace CO from H₂ for proton-exchange membrane fuel cells and offers an elaborate interface modification method to design highly efficient gold-based catalysts," said Prof. HUANG.

This work was supported by the National Natural Science Foundation of China, National Key R&D Program of China, and the Strategic Priority Research Program of the CAS.