Paolina Atanassova

Diesel oxidation catalysts

The diesel oxidation catalyst (DOC) has been part of diesel exhaust systems since regulations were introduced to limit the amount of harmful emissions released to the environment from diesel engines. The DOC primary functions are oxidation of CO, unburned hydrocarbons, and NO, while active hydrocarbon oxidation can also be used to generate exotherms required for downstream components. This review will describe work that has attempted to understand the reactions, both desired and undesired, that occur over the catalyst. First, the history, configuration, and components of the DOC will be discussed, followed by in-depth coverage of the fundamental reactions that occur over a DOC, including reaction mechanisms, reaction inhibition, and other reactivity effects. Finally, DOC deactivation mechanisms and their effects on the DOC are described. While there is a lot of research literature regarding Pt- and Pd-based catalysts for many different reaction schemes, this review tries to highlight work most relevant to DOC applications.

Advanced Materials Systems for Ultra-Low-Temperature, Digital, Direct-Write Technologies

This chapter illustrates the need for materials that can be directly written onto organic substrates at low temperatures to give materials with outstanding performance. It reviews the existing options for these materials such as polymer thick film and the constraints on materials imposed by emerging digital direct write deposition systems. The chapter emphasizes on family of new materials chemistry approaches that allow ultra-low-temperature deposition of high-performance and high-reliability materials onto organic substrates. It presents specific discussions of results for conductors, resistors, dielectrics, and phosphor materials as well. The post deposition processing on novel substrates imposes additional requirements such as chemical compatibilities and stringent processing limitations such as firing below 200°C or compatibility with laser sintering. The importance of directly written thin-form batteries fits within the overall strategy of higher levels of device integration in the portable electronics industry. These power-generating and storage devices are essential to operate the devices produced by the emerging direct write technologies.

Direct-Write Materials and Layers for Electrochemical Power Devices

This chapter explains the needs and attributes of direct-write electrochemical power devices. An electrochemical power device is defined as a device that stores or produces electrical energy. This includes batteries, fuel cells, supercapacitors, and capacitors. The chapter emphasizes on batteries and fuel cells and description of the key features of electrochemical power devices that can be improved through direct-write deposition technologies. In electrochemical power devices, direct-write technologies provide various combinations of attributes including conformality, complex patterns, fine features, digital deposition, rapid prototyping, and control over large thickness and structure. Batteries are used to power portable electronic devices while non portable devices are powered by connection to the electrical grid with electrical power supplied by power stations. With the onset of electrical power deregulation and the increasing demand for high-reliability electrical power, fuel cells are gaining momentum as potential sources for distributed power generation from devices as small as cell phones to as large as ships.