1.Well-Defined Ceria shaped catalysts with Atomic Layer Deposition technique
Using Atomic Layer Deposition (ALD) to synthesize heterogeneous catalysts with atomic level precision has gained increasing interest in recent years. In our laboratory we have synthesized well-defined heterogeneous catalysts by depositing Pt onto various CeO2 nanoshapes using ALD. The benefit of using CeO2 nanoshapes is that the surface facets of each shape are well defined, as the CeO2 octahedra have (111) surface terminations.Therefore, this allows us to determine the influence of the support oxide surface structure on the active metal and ultimately on the probe reactions.
2.Oxidative coupling of methane
Transition metal oxide usage in hydrocarbon activation, particularly lower alkanes such as methane and ethane at temperatures below 500 °C, has garnered increased attention because of the need for efficient and clean utilization of dwindling hydrocarbon feedstocks. Methane is a very strong greenhouse gas and traps far more heat than either CO or CO2; approximately twenty times as much heat as CO2 at similar concentrations, and is typically used only in the heating and electrical sectors. Therefore, there is an untapped potential in methane for application as a feedstock in the creation of value-added products such as ethane and ethylene of which ethylene is the more desirable. One potential pathway for the effective utilization of methane is in directly converting methane to ethane/ethylene through the oxidative coupling of methane reaction, which relies on the formation of methyl radicals from hydrogen abstraction to form value added products. Methane activation is readily catalyzed by noble metal catalysts, however the usage of these metals is limited by the high cost and low availability, rendering even metal nanoparticles economically unviable. To improve precious-metal efficiency, one strategy is to dope, at very low loadings, these metals into readily abundant metal oxides.
3.Sintering resistant catalysts by Atomic Layer Deposition
Heterogeneous catalysts are the most important catalyst in industry. Among all heterogeneous catalyst, supported metal catalyst is the most common. However, under higher temperature condition, the metal nanoparticles are not stabled and tend to form larger nanoparticles and deactivation. This would result many economically disadvantages such as to remake or regenerate catalysts. Here we are trying to use ALD to deposition an inert protecting layer to prevent the sintering and activation of supported metal catalysts.