Atmospheric-Pressure DBD Cold Plasma for Preparation of High Active Au/P25 Catalysts for Low-Temperature CO Oxidation

Abstract

Cold plasma generated by dielectric barrier discharge (DBD) at atmospheric pressure was adopted for preparation of commercial TiO2 Degussa P25 supported Au catalysts (Au/P25-P) with the assistance of the deposition-precipitation procedure. The influences of the plasma reduction time and calcination on the performance of the Au/P25-P catalysts were investigated. CO oxidation was performed to investigate the catalytic activity of the Au/P25 catalysts. The results show that DBD cold plasma for the fabrication of Au/P25-P catalysts is a fast process, and Au/P25-P (4 min) exhibited the highest CO oxidation activity due to the complete reduction of Au compounds and less consumption of oxygen vacancies. In order to form more oxygen vacancies active species, Au/P25-P was calcined to obtain Au/P25-PC catalysts. Interestingly, Au/P25-PC exhibited the highest activity for CO oxidation among the Au/P25 samples. The results of transmission electron microscopy (TEM) indicated that the smaller size and high distribution of Au nanoparticles are the mean reasons for a high performance of Au/P25-PC. Atmosphericpressure DBD cold plasma was proved to be of great efficiency in preparing high performance supported Au catalysts.

Atmospheric-Pressure Cold Plasma Activating Au/P25 for CO Oxidation: Effect of Working Gas

“…The order of [O] s concentration for all the Au/P25 catalysts was Au/P25-As > Au/P25-O 2 P > Au/P25-ArP > Au/P25-AirP > Au/P25-H 2 P, indicating that cold plasma activation can lead to the decline of [O] s concentration and working gas play important roles in [O] s concentration. The significant decrease in [O] s concentration for Au/P25-H 2 P may result from the consumption of [O] s by the hydrogen species [ 27 ]. Combined with the results of the proportions of metallic Au 0 and [O] s ( Table 2 ), it can be concluded that AP cold plasma can not only decompose gold precursor into metallic Au 0 but also form active [O] s on the P25 surface.…”

“…Deng et al [ 26 ] used AP oxygen cold plasma to activate Au/P25 catalysts, and found the prepared catalysts exhibited enhanced activity for visible-light photocatalytic oxidation of CO. In previous work, we adopted AP hydrogen and oxygen cold plasma to synthesize Au/TiO 2 catalysts, and obtained high performance gold catalysts [ 27 , 28 ]. The effect of discharge time and discharge voltage on the structure and property of the Au/TiO 2 catalysts are also investigated and discussed [ 29 ].…”

A review on the recent progress, challenges, and perspectives of atmospheric‐pressure cold plasma for preparation of supported metal catalysts

“…It should be noted that cold plasma recently has also been adopted to prepare supported metal catalysts combined with co‐precipitation and deposition‐precipitation methods in addition to impregnation method.…”

“…The enhanced activity was attributed to large amount of surface hydroxyl groups, as well as the abundant low‐coordinated Au species and interface active sites. Di et al prepared Au/TiO 2 catalysts by AP plate‐to‐plate DBD hydrogen cold plasma with a deposition‐precipitation process. The influence of plasma treatment time was investigated, and 4 min reduction prepared Au/TiO 2 catalyst exhibited the highest CO oxidation activity due to the complete reduction of Au ions and less consumption of the oxygen vacancies …”

Effect of ammonia‐derived species on visible‐light photocatalytic activity of Au supported on amorphous TiO2 activated by plasma

“…Cold plasma provides an innovative approach for activating Au catalysts . As reported in the literatures, cold plasma offers large numbers of energized electrons and active species for reducing Au δ+ species to Au 0 while keeping a low gas temperature, thus tending to achieve highly distributed Au 0 nanoparticles and strong metal‐support interactions. In our previous works, O 2 plasma has been successfully used to active Au photocatalysts.…”