The role of water and copper oxide in methane oxidation using AuPd nanoparticle catalysts

Methane shows great potential as a chemical feedstock, but conversion to value-added products remains a significant challenge. Selective oxidation of methane at moderate temperatures and pressures has gained momentum, with AuPd nanoparticles showing promise for methane activation. The formation of different surface intermediates is illustrated through studies with different temperatures and reaction feed compositions. The relationship between these surface intermediates and the selectivity and activity are shown. One hypothesis is that water and stabilization materials such as copper oxide facilitate selective oxidation of methane. To test this hypothesis, TiO2-supported AuPd nanoparticles with and without a copper oxide stabilizing material are used in wet and dry feed conditions. It is observed that AuPd catalysts are more active than monometallic Au and Pd catalysts at temperatures below 200 degrees C when water is present on the catalyst surface. Additionally, methane oxidation rates increase with unprotonated formate. The presence of CuOx improves methane adsorption and selectivity towards CO over CO2, but CuOx decreases overall methane consumption.

Automated summary

The selective oxidation of methane is a challenging process, but AuPd nanoparticles have shown promise in activating methane at moderate temperatures and pressures. Through experimental studies, the formation of different surface intermediates and their relationship with selectivity and activity have been explored. It has been hypothesized that water and copper oxide can facilitate the selective oxidation of methane. The results indicate that AuPd catalysts are more active than monometallic Au and Pd catalysts in the presence of water, and the unprotonated formate can increase the methane oxidation rate. Additionally, copper oxide improves the selectivity of methane towards CO but decreases the overall methane consumption.