Adsorption and reaction of CO and CO2 were studied on oxygen-covered Au（997） surfaces by means of temperature- programmed desorption/reaction spectroscopy. Oxygen atoms （O（a）） on Au（997） enhances the CO2 adsor...Adsorption and reaction of CO and CO2 were studied on oxygen-covered Au（997） surfaces by means of temperature- programmed desorption/reaction spectroscopy. Oxygen atoms （O（a）） on Au（997） enhances the CO2 adsorption and stabilizes the adsorbed COe（a）, and the stabilization effect also depends on the CO2（a） coverage and involved Au sites. CO2（a） desorp- tion is the rate-limiting step for the CO＋O（a） reaction to produce CO2 on Au（997） at 105 K and exhibits complex behaviors, including the desorption of CO2（a） upon CO exposures at 105 K and the desorption of O（a）-stabilized CO2（a） at elevated temperatures. The desorption of CO2（a） from the surface upon CO exposures at 105 K to produce gaseous CO2 depends on the surface reaction extent and involves the reaction heat-driven CO2（a） desorption channel. CO＋O（a） reaction proceeds more easily with weakly-bound oxygen adatoms at the （111） terraces than strongly-bound oxygen adatoms at the （111） steps. These re- sults reveal complex rate-limiting COe（a） desorption behaviors during CO＋O（a） reaction on Au surfaces at low temperatures which provide novel information on the fundamental understanding of Au catalysis.展开更多
基金supported by the National Basic Research Program of China (2013CB933104)National Natural Science Foundation of China (20973161, 21373192)+1 种基金Ministry of Education Fundamental Research Funds for the Central Universities (WK2060030017)Collaborative Innovation Center of Suzhou Nano Science and Technology
文摘Adsorption and reaction of CO and CO2 were studied on oxygen-covered Au（997） surfaces by means of temperature- programmed desorption/reaction spectroscopy. Oxygen atoms （O（a）） on Au（997） enhances the CO2 adsorption and stabilizes the adsorbed COe（a）, and the stabilization effect also depends on the CO2（a） coverage and involved Au sites. CO2（a） desorp- tion is the rate-limiting step for the CO＋O（a） reaction to produce CO2 on Au（997） at 105 K and exhibits complex behaviors, including the desorption of CO2（a） upon CO exposures at 105 K and the desorption of O（a）-stabilized CO2（a） at elevated temperatures. The desorption of CO2（a） from the surface upon CO exposures at 105 K to produce gaseous CO2 depends on the surface reaction extent and involves the reaction heat-driven CO2（a） desorption channel. CO＋O（a） reaction proceeds more easily with weakly-bound oxygen adatoms at the （111） terraces than strongly-bound oxygen adatoms at the （111） steps. These re- sults reveal complex rate-limiting COe（a） desorption behaviors during CO＋O（a） reaction on Au surfaces at low temperatures which provide novel information on the fundamental understanding of Au catalysis.
