Trace mono-atomically dispersed rhodium on zeolite-supported cobalt catalyst for the efficient methane oxidation

Abstract

The partial oxidation of methane is a promising method for the efficient production of syngas. To implement this process using common stainless steel reactors, an inexpensive catalyst that functions at 650 °C or below is necessary. However, base metal catalysts typically require much higher temperatures, and they are deactivated by re-oxidation and coke formation. Here we report that modification of a zeolite-supported 3 wt% cobalt catalyst with a trace amount of mono-atomically dispersed rhodium (0.005 wt%) dramatically improves catalytic performance and durability. Cobalt/mordenite is nearly inactive due to the oxidation of cobalt, but the catalyst modified with rhodium continuously gives 85–86% methane conversion and 90–91% CO selectivity with an H2/CO ratio of 2.0 without serious coking at 650 °C. During the reaction, mono-atomically dispersed rhodium converts cobalt oxide to Co0 active species via hydrogen spillover. Use of the zeolite support is key to the high catalytic performance.