文摘
Synthetically tuning the surface properties of many oxide catalysts to optimize their catalytic activity has been appreciably challenging, given their complex crystal structure. Nickelate oxides (e.g., La2NiO4+未) are among complex, layered oxides with great potential toward efficiently catalyzing chemical/electrochemical reactions involving oxygen (oxygen reduction, ammonia oxidation). Our theoretical calculations show that the surface structure of La2NiO4+未 plays a critical role in its activity, with the (001)-Ni oxide-terminated surface being the most active. This is demonstrated through the effect on the energetics associated with surface oxygen exchange, a key process in reactions involving oxygen on these oxides. Using a reverse microemulsion method, we have synthesized La2NiO4+未 nanorod-structured catalysts highly populated by (001)-Ni oxide-terminated surfaces. We show that these nanostructures exhibit superior catalytic activity toward oxygen exchange/reduction as compared with traditional catalysts while maintaining stability under reaction conditions. The findings reported here pave the way for engineering complex metal oxides with optimal activity.