Design and Fabrication of High Performance ZnO/perovskite Nano-array based Monolithic Catalysts for Automotive Emission Control

Monolithic catalyst, usually composed of honeycomb substrate and wash-coated powder-form catalysts on its channel surface, represents a unique class of functional devices that has been adapted in current industries, particularly in automotive industry as catalytic converters for engine emission aftertreatment purpose. The powder wash-coat based monolithic catalyst lacks well-defined structural configuration in particulate size, shape and distribution, leading to usually compromised materials utilization efficiency and catalytic activity. Thus, it is necessary to develop new generation of high performance monolithic catalysts to meet the increasingly stringent emission regulation. Perovskite materials have been studied as potential candidate of automotive catalysts for decades, with their excellent thermal stability and redox ability allowing them being promising catalysts for heterogeneous catalytic reactions at high temperature. In this dissertation, we introduce design and manufacturing of large-scale high performance ZnO/perovskite nano-array based monolithic catalysts. Detailed discussions are focused on catalytic activity enhancement via rational materials selection and structural manipulation. Noble metal incorporation, acid treatment effect and hydrothermal stability are further studied. The Pt incorporated catalysts exhibit good catalytic performance towards propane oxidation with good hydrothermal stability. The acid treated perovskite nano-array catalysts possess enhanced low temperature activity due to the evolution of nanostructure and surface chemistry. With the successful demonstration of industrially-relevant integration strategy, ZnO/perovskite nano-array catalysts show promise as a new type of monolithic catalysts for automotive emission control