Lowering the Operating Temperature of Gold Acetylene Hydrochlorination Catalysts Using Oxidized Carbon Supports

The commercialization of gold for acetylene hydrochlorination represents a major scientific landmark. The development of second-generation gold catalysts continues with a focus on derivatives and drop-in replacements with higher activity and stability. Here, we show the influence that the support surface oxygen has on the activity of carbon supported gold catalysts. Variation in the surface oxygen content of carbon is achieved through careful modification of the Hummers chemical oxidation method prior to the deposition of gold. All oxidized carbon-based catalysts resulted in a marked increase in activity at 200 degrees C when compared to the standard nontreated carbon, with an optimum oxygen content of ca. 18 at % being observed. Increasing oxygen and relative concentration of C-O functionality yields catalysts with light-offtemperatures 30-50 degrees C below the standard catalyst. This understanding opens a promising avenue to produce high activity acetylene hydrochlorination catalysts that can operate at lower temperatures.

Automated summary

The commercialization of gold for acetylene hydrochlorination is a significant achievement in the field. The development of second-generation gold catalysts aims to enhance their activity and stability. This study demonstrates that the surface oxygen content of carbon-based gold catalysts affects their activity. By modifying the Hummers chemical oxidation method before gold deposition, the oxygen content of carbon can be adjusted. The oxidized carbon-based catalysts exhibit higher activity at lower temperatures compared to untreated carbon, with an optimum oxygen content of around 18%. Increasing the oxygen content and concentration of C-O functionality lowers the catalyst's light-off temperature, offering a potential approach to produce highly active acetylene hydrochlorination catalysts.